[PWGDQ] Fix precompiled header

[vkucera]

• Rename cxx to h, as already requested in [PWGDQ] Split the table-reader-with-assoc into several workflow specs #16863
• Replace pragma once with a proper header guard. This allows proper analysis by Clang-Tidy and avoids false positives about redefinitions. FYI: @ktf
• Fully qualify names and remove using directives and declarations.
• Fix Doxygen documentation.

[github-actions]

O2 linter results: ❌ 385 errors, ⚠️ 176 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 6d98d8d at 2026-09-06 01:14:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 12 errors and 8 warnings.'
Found 12 errors and 8 warnings.
++ [[ 12 -gt 0 ]]
++ cat /sw/BUILD/a02a9a81742c9ee142c7bebb6b6c8cf878a673e9/O2Physics-code-check/errors.txt
PWGDQ/Tasks/dqEfficiency_withAssoc.cxx:595:30: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/dqEfficiency_withAssoc.cxx:918:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/dqEfficiency_withAssoc.cxx:3462:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:82:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:84:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:85:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:86:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:87:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:88:1: error: using declarations in the global namespace in headers are prohibited [google-global-names-in-headers,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:721:30: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:990:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:3270:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
++ [[ 8 -gt 0 ]]
++ cat /sw/BUILD/a02a9a81742c9ee142c7bebb6b6c8cf878a673e9/O2Physics-code-check/warnings.txt
PWGDQ/Tasks/tableReader_withAssoc.h:1936:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3576:9: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3577:9: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3776:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3777:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:4258:5: warning: use auto when initializing with a template cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:4627:19: warning: implicit conversion 'uint32_t' (aka 'unsigned int') -> 'bool' [readability-implicit-bool-conversion]
PWGDQ/Tasks/tableReader_withAssoc.h:4675:19: warning: implicit conversion 'uint32_t' (aka 'unsigned int') -> 'bool' [readability-implicit-bool-conversion]
++ [[ 12 -gt 0 ]]
++ exit 1
--

Full log here.

[alibuild]

Error while checking build/O2Physics/code-check for ce9a208 at 2026-09-06 17:16:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 6 errors and 8 warnings.'
Found 6 errors and 8 warnings.
++ [[ 6 -gt 0 ]]
++ cat /sw/BUILD/2a393f2a219abfeb3c3230a0c339c15c39bd6dc1/O2Physics-code-check/errors.txt
PWGDQ/Tasks/dqEfficiency_withAssoc.cxx:595:30: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/dqEfficiency_withAssoc.cxx:918:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/dqEfficiency_withAssoc.cxx:3462:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:715:30: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:984:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGDQ/Tasks/tableReader_withAssoc.h:3264:29: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
++ [[ 8 -gt 0 ]]
++ cat /sw/BUILD/2a393f2a219abfeb3c3230a0c339c15c39bd6dc1/O2Physics-code-check/warnings.txt
PWGDQ/Tasks/tableReader_withAssoc.h:1930:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3570:9: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3571:9: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3770:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:3771:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:4252:5: warning: use auto when initializing with a template cast to avoid duplicating the type name [modernize-use-auto]
PWGDQ/Tasks/tableReader_withAssoc.h:4621:19: warning: implicit conversion 'uint32_t' (aka 'unsigned int') -> 'bool' [readability-implicit-bool-conversion]
PWGDQ/Tasks/tableReader_withAssoc.h:4669:19: warning: implicit conversion 'uint32_t' (aka 'unsigned int') -> 'bool' [readability-implicit-bool-conversion]
++ [[ 6 -gt 0 ]]
++ exit 1
--

Full log here.