Add scaffolding for role explanation endpoint

[mabashian]

Jira Issue: https://issues.redhat.com/browse/AAP-39792

Description

An attempt to scaffold in the role explanation endpoint

Testing

Steps to test

1. Pull down the PR
2. Check out the swagger api schema and compare against proposal in Jira
3. Ensure unit tests run successfully

Scenarios tested

Production deployment

• This code change is ready for production on its own
• This code change requires the following considerations before going to production:

[manstis]

LGTM 👍 (A small comment, but harmless nonetheless).

You're the first developer to make new changes using:

• Versioned API
• AACSAPIView base class

You're also one of the first to make new changes using:

• ai/api/model_pipelines

What was your experience?

[mabashian]

@manstis most (really almost all) of this work was simply following the patterns already established but I didn't find it too cumbersome to work with this architecture. If I'm honest I'm still a bit confused on whether this endpoint should be added to v0. It's currently included in the v0 urls but should it only be available in v1?

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
90.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud