Reorganize: Move test_m* unit tests into files/directories that mimic source code being tested

[QMalcolm]

Housekeeping

• I am a maintainer of dbt-core

Short description

As part of our Robust Testing Initiative we want to re-organize our unit tests to mimic the source code directory and files. Doing one file is generally smaller than what we'd rank as one unit of work, so this is a grouping of multiple. Here we want take unit tests in unit test files starting with test_m* and reorganize them into appropriate files within appropriate directories. This includes: test_macro_calls.py, test_macro_resolver.py, test_manifest_selectors.py, and test_manifest.py. These files contain 28 unit tests.

Acceptance criteria

The unit tests in test_macro_calls.py, test_macro_resolver.py, test_manifest_selectors.py, and test_manifest.py have been moved to files within a directory structure under tests/unit/ that mirror the organization of the source code being tested.

Suggested Tests

The work is the tests

Impact to Other Teams

None

Will backports be required?

Narp

Context

#9649

[QMalcolm]

And add some comments perhaps

[QMalcolm]

Duplicate of #9961