[tooling] Update schema generation

[BenjaminPelletier]

We automatically generate JSON Schema for some of our data classes to help users manage our complex nested data structures. Previously, we simply tried to import the right modules and then search through the loaded modules for schemas to generate. This PR refines/fixes that approach by specifically targeting only and all the schemas needed to describe:

• USSQualifierConfiguration (the input to uss_qualifier)
• TestRunReport (the output from uss_qualifier)
• Any types used as specifications for Resources (these are not strongly-typed in the configuration)
• Any types used as specifications for ActionGenerators (these are not strongly-typed in the configuration)

The first commit of this PR is just the code changes (including two bug fixes in Resource definitions), then the second commit is the consequence of deleting all the old schemas and then regenerating them. The latter commit has more changes than is absolutely necessary because a while back we switched to sort_keys=True when writing the JSON, but we don't overwrite old content if its data content is correct (just its keys are out of order).

[barroco]

👍 (Another reason for the big changeset is the usage of qualname (in fullname) instead of name to describe field names.)