Apply buildifier linter suggestions

[furtib]

Why:
We want to produce high quality bazel code. To do this, we use buildifier to both format and lint our files.

What:

• Applied all* linter suggestions to bzl files

*: In per_file.bzl in the run_code_checker function I puposefully ignored the unused variable errors. This function is still in early development, and the unused variables (arguments, label, env_vars, compilation_context) may be necessary in the future.

Addresses:
#155

[furtib]

Note:
You might notice that the ctx argument is documented over and over again, despite its obvious meaning.
This documentation step can be avoided if we rename the variable to _ctx.
What are your thoughts on this?