Adds unique pda ringtones for jobs (#71317)

## About The Pull Request
Bringing back a feature of legacy pdas that was criminally
underutilized!

Brings back legacy ringtones. Also, refactored update_ringtone to make
it more consistent to set a ringtone on a pda
## Why It's Good For The Game
Fun mixup, and it would be nice to see more than just \*\*beep** since
nobody sets their ringtone
## Changelog
🆑
add: Re-adds legacy job ringtones (clown, mime, jani, lawyer, science,
chaplain)
refactor: update_ringtone was modifed to accept strings, moving the old
functionality to update_ringtone_pref
/🆑

Co-authored-by: Candycaneannihalator <candycane@thisisnotarealaddr.com>
Co-authored-by: Mothblocks <35135081+Mothblocks@users.noreply.github.com>

code/modules/modular_computers/computers/item/tablet.dm

@@ -199,7 +199,7 @@
  * Arguments:
  * * ringtone_client - The client whose prefs we'll use to set the ringtone of this PDA.
  */
-/obj/item/modular_computer/tablet/proc/update_ringtone(client/ringtone_client)
+/obj/item/modular_computer/tablet/proc/update_ringtone_pref(client/ringtone_client)
 	if(!ringtone_client)
 		return
 
@@ -208,10 +208,16 @@
 	if(!new_ringtone || new_ringtone == MESSENGER_RINGTONE_DEFAULT)
 		return
 
+	update_ringtone(new_ringtone)
+
+
+/// A simple proc to set the ringtone from a pda.
+/obj/item/modular_computer/tablet/proc/update_ringtone(new_ringtone)
+	if(!istext(new_ringtone))
+		return
 	for(var/datum/computer_file/program/messenger/messenger_app in stored_files)
 		messenger_app.ringtone = new_ringtone
 
-
 // SUBTYPES
 
 /obj/item/modular_computer/tablet/syndicate_contract_uplink