A mapping between GTFS files and Validators

[qcdyx]

Describe the problem

Related to Issue https://github.com/MobilityData/gtfs-validator/issues/1537 and PR https://github.com/MobilityData/gtfs-validator/pull/1565.

If the input GTFS file doesn't contain certain text files, then the corresponding validators should not run.

Proposed solution

A mapping between GTFS files and validators should be established based on the schemas of each validator.

Alternatives you've considered

No response

Additional context

No response