fix: ape compile source import references

[NotPeopling2day]

What I did

Added logic for fetching referenced imports

partial fix for ApeWorX/ape#623
unblocks @sabotagebeats ApeWorX/ape#81

How I did it

Read each source path and pull out imports
Add cleaned import strings to dictionary

How to verify it

Ape core implementation ApeWorX/ape#730

Checklist

• Passes all linting checks (pre-commit and CI jobs)
• New test cases have been added and are passing
• Documentation has been updated
• PR title follows Conventional Commit standard (will be automatically included in the changelog)

[NotPeopling2day]

Type-check currently doesn't pass because of a method I'm adding in core. I'm planning on sharing that logic between the different compilers to lookup the filename in the given paths.

[antazoey]

Test cases that would be nice:

1. Relative imports from same directory
2. Relative imports when going up a directory (../)
3. Imports that are part of a remapping (?)

[antazoey]

This is looking good! What is missing?

[antazoey]

def test_get_import_remapping(compiler, project, config):
    import_remapping = compiler.get_import_remapping()

    with config.using_project(project.path / "dependency"):
        # Should be different now that we have changed projects.
        second_import_remapping = compiler.get_import_remapping()

    assert import_remapping != second_import_remapping

[antazoey]

def test_get_import_remapping(compiler, project, config):
    import_remapping = compiler.get_import_remapping()

    with config.using_project(project.path / "dependency"):
        # Should be different now that we have changed projects.
        second_import_remapping = compiler.get_import_remapping()

    assert import_remapping != second_import_remapping