Based on the updated design doc, this issue implements the support for group of users in manual approval gate 

Acceptance Criteria:

• With existing multiple users approval, manual approval should also have support for group of users
• Until and unless approval task does not get approval from the users as true, till that approvalState will be `wait`
• If any one use disapproves the approval task we will mark the approvalState as false and then the pipelinerun will fai l
• If a user approves for the first time and still approvalsRequired limit is not reached i.e. approvalState is `wait` then user can still change his input and mark the approval task as `false`
• Approvals from both type as `user` and type as `group` is allowed at once