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

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

Modules/Spotter.lua

@@ -177,7 +177,7 @@ function shared.Spotter.Init()
 
 		---@type Message
 		local msg = {
-			channel = "CHANNEL",
+			channel = "C",
 			data = Heimdall_Data.config.spotter.notifyChannel,
 			message = text
 		}
@@ -220,7 +220,7 @@ function shared.Spotter.Init()
 			x * 100, y * 100)
 		if Heimdall_Data.config.essencex.spotter and Heimdall_Data.config.essencex.enabled then
 			local msg = {
-				channel = "CHANNEL",
+				channel = "C",
 				data = Heimdall_Data.config.essencex.masterChannel,
 				message = text
 			}
@@ -234,7 +234,7 @@ function shared.Spotter.Init()
 		if Heimdall_Data.config.echoToRussian then
 			-- Russian message
 			local ruMsg = {
-				channel = "CHANNEL",
+				channel = "C",
 				data = Heimdall_Data.config.spotter.notifyChannel .. "ru",
 				message = text
 			}