🚚 Move all enums to there respective headers

Source/tmsg.h

@@ -7,25 +7,19 @@
 
 namespace devilution {
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #pragma pack(push, 1)
-typedef struct TMsg TMsg;
-
-typedef struct TMsgHdr {
-	TMsg *pNext;
+struct TMsgHdr {
+	struct TMsg *pNext;
 	Sint32 dwTime;
 	Uint8 bLen;
-} TMsgHdr;
+};
 
-typedef struct TMsg {
+struct TMsg {
 	TMsgHdr hdr;
 	// this is actually alignment padding, but the message body is appended to the struct
 	// so it's convenient to use byte-alignment and name it "body"
 	Uint8 body[3];
-} TMsg;
+};
 #pragma pack(pop)
 
 int tmsg_get(Uint8 *pbMsg, Uint32 dwMaxLen);
@@ -33,8 +27,4 @@ void tmsg_add(Uint8 *pbMsg, Uint8 bLen);
 void tmsg_start();
 void tmsg_cleanup();
 
-#ifdef __cplusplus
-}
-#endif
-
 }