docs(prism-agent): add verification policy OpenAPI description

[yshyn-iohk]

Overview

Fixes ATL-6268 - improve OpenAPI specification for Verification Policies API

Checklist

My PR contains...

• No code changes (changes to documentation, CI, metadata, etc.)
• Bug fixes (non-breaking change which fixes an issue)
• Improvements (misc. changes to existing features)
• Features (non-breaking change which adds functionality)

My changes...

• are breaking changes
• are not breaking changes
• If yes to above: I have updated the documentation accordingly

Documentation

• My changes do not require a change to the project documentation
• My changes require a change to the project documentation
• If yes to above: I have updated the documentation accordingly

Tests

• My changes can not or do not need to be tested
• My changes can and should be tested by unit and/or integration tests
• If yes to above: I have added tests to cover my changes
• If yes to above: I have taken care to cover edge cases in my tests

[sonarqubecloud]

Quality Gate passed

The SonarCloud Quality Gate passed, but some issues were introduced.

5 New issues
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

Integration Test Results

11 files  ±0  11 suites  ±0   2s ⏱️ ±0s
24 tests ±0  24 ✅ ±0  0 💤 ±0  0 ❌ ±0 
25 runs  ±0  25 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 38594fa. ± Comparison against base commit 614e811.

[github-actions]

Unit Test Results

 85 files  ±0   85 suites  ±0   21m 17s ⏱️ +12s
713 tests ±0  705 ✅ ±0  8 💤 ±0  0 ❌ ±0 
719 runs  ±0  711 ✅ ±0  8 💤 ±0  0 ❌ ±0 

Results for commit 38594fa. ± Comparison against base commit 614e811.

[bvoiturier]

One more step in the right direction! Well done @yshyn-iohk 💪