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/BuddyManager.hpp

@@ -36,5 +36,6 @@ namespace BuddyManager {
 	// helper methods
 	
 	// Name checks
+	int getAvailableBuddySlot(Player* plr);
 	bool NameCheck(char16_t reqName[], char16_t resName[], int sizeOfReq, int sizeOfRes); // checks if the request and requested player's names match
 }