Shorten every instance of "CHANNEL" to "C" and whisper too

To save a little space in messages, it's getting very cramped

Modules/Noter.lua

@@ -115,7 +115,7 @@ function shared.Noter.Init()
 		end
 		---@type Message
 		local msg = {
-			channel = "CHANNEL",
+			channel = "C",
 			data = Heimdall_Data.config.noter.masterChannel,
 			message = string.format("[%s][%d] %s: %s", note.source, index, note.date, note.note)
 		}