literally just hook asay into tgui say (#73212)

## About The Pull Request

pressing f3 now opens asay in tgui say
## Why It's Good For The Game

![john willard gets
banned](https://user-images.githubusercontent.com/12202230/216750445-addb4f3f-0df4-47da-891d-4ef4820a10ab.png)

also fixes double-escaped special characters caused by #72407 and
finally gets rid of the gross regular tgui input popup
## Changelog
🆑
fix: asays are no longer double-escaped
admin: asay now uses tgui say
/🆑

---------

Co-authored-by: Scriptis <scriptis@duck.com>

code/modules/tgui_input/say_modal/modal.dm

@@ -82,7 +82,7 @@
 	if(!payload?["channel"])
 		CRASH("No channel provided to an open TGUI-Say")
 	window_open = TRUE
-	if(payload["channel"] != OOC_CHANNEL)
+	if(payload["channel"] != OOC_CHANNEL && payload["channel"] != ADMIN_CHANNEL)
 		start_thinking()
 	if(client.typing_indicators)
 		log_speech_indicators("[key_name(client)] started typing at [loc_name(client.mob)], indicators enabled.")

code/modules/tgui_input/say_modal/speech.dm

@@ -44,6 +44,9 @@
 		if(OOC_CHANNEL)
 			client.ooc(entry)
 			return TRUE
+		if(ADMIN_CHANNEL)
+			client.cmd_admin_say(entry)
+			return TRUE
 	return FALSE
 
 /**