FE: Allow users to specify more than one required approval actions in Policy UI Editor

Why are we doing this work

In the scope of this issue, we would like to deliver the required changes to allow users to specify multiple approval actions in the Policy UI Editor for Merge Request Approval Policy. We should limit max number of require approval actions to 5.

Relevant links

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan

Verification steps