customize list of identifiers in ast collection

[luxass]

Clear and concise description of the problem

The AST collection currently uses a hardcoded list of test function identifiers ['it', 'test', 'describe', 'suite'].

This prevents proper test discovery when using extended test contexts or custom test function names that don't match these predefined identifiers.

I will gladly open a PR for this, if this is a welcoming change :)

Suggested solution

Add support for customizing the list of identifiers

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.