Clear PDAs now specify they are a crystal PDA in messenger (#76675)

## About The Pull Request

When you say "sent from my PDA" in messenger, if it's through a clear
PDA, it will instead say "Sent from my Crystal PDA". This is so the
recipient knows they are in the presence of a crystal pda.

## Why It's Good For The Game

Bragging rights for having a crystal PDA. Minor interaction I think
would be funny.

## Changelog

🆑
add: The 'Sent from my PDA' message is different for Clear PDAs now
(specifying they are crystal).
/🆑

code/modules/modular_computers/file_system/programs/ntmessenger.dm

@@ -291,8 +291,8 @@
 	if(ishuman(user))
 		var/mob/living/carbon/human/old_person = user
 		sent_prob = old_person.age >= 30 ? 25 : sent_prob
-	if (prob(sent_prob))
-		message += " Sent from my PDA"
+	if (computer && prob(sent_prob))
+		message += " [computer.get_messenger_ending()]"
 
 	var/datum/signal/subspace/messaging/tablet_msg/signal = new(computer, list(
 		"name" = fake_name || computer.saved_identification,