- update: auth system to work with the website auth

proto/character_db_api.proto

@@ -23,7 +23,7 @@ message CharacterListResponse {
 }
 
 message CreateCharacterRequest {
-  int32 user_id = 1;
+  string user_id = 1;
   string name = 2;
   string inventory = 3; // JSON serialized
   string skills = 4;    // JSON serialized
@@ -50,7 +50,7 @@ message DeleteCharacterResponse {
 
 message Character {
   int32 id = 1;
-  int32 user_id = 2;
+  string user_id = 2;
   string name = 3;
   int64 money = 4;
   string inventory = 6;