Implemented Global Chat

Added global chat feature, so players can still maintain global communication while being in their own clan chat
An individual player can opt out of global chat by using the ::muteglobal command
Implemented automatic message splitting for clan and global chat
Implemented colour selection for global chat (prefix your message with hex colour code, e.g. //%690420 before the message)

Server/src/main/core/ServerConstants.kt

@@ -264,5 +264,8 @@ class ServerConstants {
 
 		@JvmField
 		var DRAGON_AXE_USE_OSRS_SPEC = false
+
+		@JvmField
+		var ENABLE_GLOBALCHAT = false
 	}
 }