SAT: Validate that configs generated with previous spec are valid according to new spec

[pedroslopez]

(more context in parent issue #14097)

Complementary to the specific assertions introduced in #14593, we can more generically check that configs created according to the old spec are still valid according to the new spec. This can be done by generating multiple config variations with the old spec's schema, and validating them with the new spec's schema.

Implementation

There are tools out there that can already generate data for us according to a desired JSON schema.

Some options:

• hypothesis-jsonschema is a strategy for hypothesis that does this.
• Faker
• jsf