feat(anta): add AntaCatalog.dump() and AntaCatalog.merge()

[mtache]

• feat: add AntaCatalog.dump() and AntaCatalog.merge()
• ci: add unit tests for anta.catalog module

Description

This PR also includes functions to merge AntaCatalog instances and dump as a YAML file:

• AntaCatalog.merge() -> AntaCatalog
• AntaCatalog.dump() -> AntaCatalogFile
• AntaCatalogFile.yaml()

Script example:

#!/usr/bin/env python
from anta.catalog import AntaCatalog

from pathlib import Path
from anta.models import AntaTest


CATALOG_SUFFIX = '-catalog.yml'
CATALOG_DIR = 'intended/test_catalogs/'

if __name__ == "__main__":
    catalog = AntaCatalog()
    for file in Path(CATALOG_DIR).glob('*'+CATALOG_SUFFIX):
        c = AntaCatalog.parse(file)
        device = str(file).removesuffix(CATALOG_SUFFIX).removeprefix(CATALOG_DIR)
        print(f"Merging test catalog for device {device}")
        # Apply filters to all tests for this device
        for test in c.tests:
            test.inputs.filters = AntaTest.Input.Filters(tags=[device])
        catalog.merge(c)
    with open(Path('anta-catalog.yml'), "w") as f:
        f.write(catalog.dump().yaml())

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have run pre-commit for code linting and typing (pre-commit run)
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes (tox -e testenv)

[gmuloc]

I think we should put back the ValueError we had as it is a bit clearer than the cryptic pydantic error.