Merge branch 'mr-commented-by' into 'master'

Add a basic placeholder field for `commented_by`

See merge request gitlab-org/gitlab!38580

ee/lib/ee/api/entities/merge_request_approval_state_rule.rb

@@ -7,6 +7,8 @@ module EE
         expose :code_owner
         expose :approved_approvers, as: :approved_by, using: ::API::Entities::UserBasic
         expose :approved?, as: :approved
+
+        expose :approved_approvers, as: :commented_by, using: ::API::Entities::UserBasic
       end
     end
   end

ee/spec/requests/api/merge_request_approvals_spec.rb

@@ -174,6 +174,7 @@ RSpec.describe API::MergeRequestApprovals do
       expect(rule_response['name']).to eq('foo')
       expect(rule_response['approvers'][0]['username']).to eq(approver.username)
       expect(rule_response['approved_by'][0]['username']).to eq(approver.username)
+      expect(rule_response['commented_by'][0]['username']).to eq(approver.username)
       expect(rule_response['source_rule']).to be_nil
       expect(rule_response['section']).to be_nil
     end