[OpenAPI-1.2] Add MR CI to test if spec file is up to date

For each of the following repos:

• Card
• Photo
• Staff
• Student
• Institution Identifiers

• Add a (standardised) script to produce production OpenAPI spec.
• Add Merge Request CI test that uses this to produce the spec from source and fails if there is a non-empty diff (log diff).

Note:

• Institution Identifiers repo may not have a way to generate a spec
• Lookup spec generation is a mess so should be looked at later!