Configuration refactor

[garciampred]

This PR migrates dataset-specific runtime configuration out of cdsobs and into external service definition files from cads-obs-config.

What changed

• Moved dataset config fields (tile sizes, reader, ingestion DB, available CDM tables, disabled fields, etc.) into ServiceDefinition.
• Simplified CDSObsConfig:
  • Removed embedded datasets/DatasetConfig.
  • Renamed config path key to cads_obs_config_location.
• Updated service-definition loading to read cads-obs-config/service-definitions/.yml
• Refactored ingestion/retrieve/forms/api flows to use ServiceDefinition as the source of truth.
• Added optional service_definition injection in key API functions (run_ingestion_pipeline, run_make_cdm, get_forms_jsons) for the tests.
• Updated CI to clone cads-obs-config instead of cads-forms-insitu.
• Expanded type hints across modules and tightened coverage config (pyproject.toml, Makefile).
• Updated tests/fixtures to build dataset behavior from service-definition files and removed legacy dataset config test data.
• Remove setup.cfg, use only pyproject.toml.