Buddy code cleanup

- Get rid of buddyCnt, self-nullptr checks, and redundant playermap loops in chat handlers
- Add helper function to find available buddy slot
- Reorganize a bit

src/Player.hpp

@@ -71,6 +71,5 @@ struct Player {
 
     bool notify;
 
-    int buddyCnt;
     int64_t buddyIDs[50];
 };