Set the policy mapping for a user or group (#8036)

Add API to set policy mapping for a user or group

Contains a breaking Admin APIs change.

- Also enforce all applicable policies
- Removes the previous /set-user-policy API

 Bump up peerRESTVersion

Add get user info API to show groups of a user

cmd/notification.go

@@ -189,6 +189,21 @@ func (sys *NotificationSys) LoadPolicy(policyName string) []NotificationPeerErr
 	return ng.Wait()
 }
 
+// LoadPolicyMapping - reloads a policy mapping across all peers
+func (sys *NotificationSys) LoadPolicyMapping(userOrGroup string, isGroup bool) []NotificationPeerErr {
+	ng := WithNPeers(len(sys.peerClients))
+	for idx, client := range sys.peerClients {
+		if client == nil {
+			continue
+		}
+		client := client
+		ng.Go(context.Background(), func() error {
+			return client.LoadPolicyMapping(userOrGroup, isGroup)
+		}, idx, *client.host)
+	}
+	return ng.Wait()
+}
+
 // DeleteUser - deletes a specific user across all peers
 func (sys *NotificationSys) DeleteUser(accessKey string) []NotificationPeerErr {
 	ng := WithNPeers(len(sys.peerClients))