Move approvals to metadata

[gdupontf]

Context

This resource produces a new version even when only the approval count has changed.
It doesn't make much sense to trigger a whole new build on approvals alone, especially when the configured minimum approvals hasn't changed.

I have simply removed the approvals count from the versions produced in gets and added it to the metadata instead.

Test Plan

Tested locally using 1.21.9.

Mitigation

This is kinda breaking, so I'd expect this in a major release bump.
At the same time I struggle to see who could have possibly benefited from current behaviour.
This could be put behind a feature flag, I'm just very beginner with Go so I'd need help.

Checklist

• I have commented my code, particularly in hard-to-understand areas
  N/A
• I have made corresponding changes to external documentation if necessary (READMEs, Confluence, etc.)
  Will be done after confirming whether or not this needs a feature flag.
• I have checked that other PRs this PR depends on have already been deployed.
• I can confirm that if this PR introduces a DB schema change, I have read and followed all the steps outlined in the Data Contract.
  N/A

[gdupontf]

Any way to get eyes on this?