feat: implement export filter functionality for resource exports

[Gijsreyn]

PR Summary

Adds engine-side post-filtering for export via a new exportFilter resource directive.

PR Context

Fixes #1486.

[Copilot]

Pull request overview

Implements engine-side post-filtering for dsc config export results via a new exportFilter resource directive, enabling consistent wildcard/equality filtering even for resources that don’t implement native export filtering.

Changes:

• Adds exportFilter to the configuration resource directives schema and applies it in the export pipeline after resource.export(...).
• Introduces configure::export_filter matching logic (case-insensitive * wildcard for strings; OR across filter objects, AND within each object) plus unit tests.
• Adds Pester coverage for exportFilter behavior and updates the dsctest export resource to emit a name property for filtering.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tools/dsctest/src/main.rs	Emits per-instance name values to enable filter-driven tests.
tools/dsctest/src/export.rs	Extends the test export payload schema with optional name.
lib/dsc-lib/src/dscresources/command_resource.rs	Adjusts when “export filtering not supported” is raised (only for non-empty input).
lib/dsc-lib/src/configure/mod.rs	Wires exportFilter from directives into the export pipeline.
lib/dsc-lib/src/configure/export_filter.rs	Adds the engine-side filtering implementation + Rust unit tests.
lib/dsc-lib/src/configure/config_doc.rs	Adds export_filter directive field to the config document model/schema.
lib/dsc-lib/locales/en-us.toml	Adds localized message for filter reduction logging.
dsc/tests/dsc_export.tests.ps1	Adds integration tests validating exportFilter behavior across scenarios.
dsc/src/resource_command.rs	Updates call site for the changed export helper function signature.

[SteveL-MSFT]

Changes look fine, but can you remove the wildcard filtering support in the service, firewall, and dism resources? I would expect all the tests to still pass (assuming they don't call the resource exe directly, if so, they would need to be udpated to go through dsc).

[Gijsreyn]

@SteveL-MSFT - good catch, but it had some caveats. I've replaced them with tests that append * to a known valid identifier. Exact-match and existing AND/OR filtering coverage remained in place.

[Copilot]

Pull request overview

Copilot reviewed 26 out of 26 changed files in this pull request and generated 3 comments.

[SteveL-MSFT]

@Gijsreyn you have a test failure and can you see if you can improve the code coverage?

[Gijsreyn]

@SteveL-MSFT - I'm a bit surprised by the coverage report. The previous run was 41%, and after adding more tests, it dropped to 21% in the latest one.

[SteveL-MSFT]

@Gijsreyn let me look into the CC report, I think the problem is that deleted lines is being calculated wrong as not covered

[SteveL-MSFT]

@Gijsreyn as part of this PR https://github.com/PowerShell/DSC/pull/1566/changes#diff-3c6f13d4710c208b61e3b3b90dd39808010bd0ef8788005fd7ee23812fcb4e9dR1504, there is a new property in the resource manifest indicating it doesn't support filtering so it all gets handled by the engine. I would expect all the resources mentioned here would have that set and not do any comparisons within the resource and simply returns all instances. Be sure to pick up the last commit that fixes the codecoverage.