API: add option to fetch only tags from ListInbounds (#4870)

* feat: add new method for get only inbound tags from core. ListTags.

* refactor: simplify creating response.

* refactor: move getting tags in already exist method via option.

app/proxyman/command/command.proto

@@ -37,7 +37,9 @@ message AlterInboundRequest {
 
 message AlterInboundResponse {}
 
-message ListInboundsRequest {}
+message ListInboundsRequest {
+  bool isOnlyTags = 1;
+}
 
 message ListInboundsResponse {
   repeated core.InboundHandlerConfig inbounds = 1;