add minimum number of approver for each group defined as approver of MR
Description
When setting the MR approvers, one can define several groups as approvers, and one can define the minimum number of approvers for the MR. Ex: I define group_A and group_B as approvers of my MR, with a minimum of 2 approvers. If 2 people from group_A approve my MR, the MR can be merged with nobody from group_B that needs to approve it.
Proposal
To be able to set a minimum number of approvers per group in the MR settings. Thus, we are sure that at least one people from each group of approver need to review the MR before merging it.