Add more details to Protected Branches audit events
In projects settings, Audit Events for `Project > Settings > Repository > Protected Branches` are basics:

## Audit need
Sometimes auditors need to have more details on what has changed regarding Protected Branches, ie:
- Which Users/Groups were added/removed to `Allowed to Merge`
- Which Users/Groups were added/removed to `Allowed to Push`
- Track changes on `Allowed to force push` option
- Track changes on `Require Codeowners approval` option
## Proposal
My proposal is to improve these Audit Events, ie:
For changes on protected branches:

issue