chore: cache_name will be provided in header rather than proto

proto/leaderboard.proto

@@ -130,64 +130,64 @@ enum _Order {
 }
 
 message _DeleteLeaderboardRequest {
-  string cache_name = 1;
   string leaderboard = 2;
+  reserved 1;
 }
 
 message _GetLeaderboardLengthRequest {
-  string cache_name = 1;
   string leaderboard = 2;
+  reserved 1;
 }
 
 message _GetLeaderboardLengthResponse {
   uint32 count = 1;
 }
 
 message _UpsertElementsRequest {
-  string cache_name = 1;
   string leaderboard = 2;
   // You can have up to 8192 elements in this list.
   repeated _Element elements = 3;
+  reserved 1;
 }
 
 message _GetByRankRequest {
-  string cache_name = 1;
   string leaderboard = 2;
   _RankRange rank_range = 3;
   _Order order = 4;
+  reserved 1;
 }
 
 message _GetByRankResponse {
   repeated _RankedElement elements = 1;
 }
 
 message _GetRankRequest {
-  string cache_name = 1;
   string leaderboard = 2;
   repeated uint32 ids = 3;
   _Order order = 4;
+  reserved 1;
 }
 
 message _GetRankResponse {
   repeated _RankedElement elements = 1;
 }
 
 message _RemoveElementsRequest {
-  string cache_name = 1;
   string leaderboard = 2;
   // You can have up to 8192 ids in this list.
   repeated uint32 ids = 3;
+  reserved 1;
 }
 
 message _GetByScoreRequest {
-  string cache_name = 1;
   string leaderboard = 2;
   _ScoreRange score_range = 3;
   // Where should we start returning scores from in the elements within this range?
   uint32 offset = 4;
   // How many elements should we limit to returning? (8192 max)
   uint32 limit_elements = 5;
   _Order order = 6;
+  reserved 1;
 }
 
 message _GetByScoreResponse {