Switch to using an enum for API ID constants.

bemani/api/objects/base.py

@@ -1,7 +1,7 @@
 from typing import List, Any, Dict
 
 from bemani.api.exceptions import APIException
-from bemani.common import GameConstants
+from bemani.common import APIConstants, GameConstants
 from bemani.data import Data
 
 
@@ -20,5 +20,5 @@ class BaseObject:
         self.version = version
         self.omnimix = omnimix
 
-    def fetch_v1(self, idtype: str, ids: List[str], params: Dict[str, Any]) -> Any:
+    def fetch_v1(self, idtype: APIConstants, ids: List[str], params: Dict[str, Any]) -> Any:
         raise APIException('Object fetch not supported for this version!')