[MIRROR] Removes some unused mob verbs + client vars [MDB IGNORE] (#12438)

* Removes some unused mob verbs + client vars (#65732)

* Removes an unused var from /client
`inprefs` isn't used anywhere, i checked to when it was added (~5 years
ago) and it wasn't even really used then. I think it used to be used to
track topic calls / slowdown some href issues but it isn't any more.
Byebye!!

* Removes some unused mob verbs + client var
`canface` and `east/west/north/southface` used to be used to set
direction but these are no longer used and are thus taking up
unnecessary space

* Removes some unused mob verbs + client vars

* Update pixel_shift.dm

Co-authored-by: Seth Scherer <supernovaa41@gmx.com>
Co-authored-by: Gandalf <9026500+Gandalf2k15@users.noreply.github.com>

code/modules/client/client_defines.dm

@@ -70,8 +70,6 @@
 		/////////
 	///Player preferences datum for the client
 	var/datum/preferences/prefs = null
-	///last turn of the controlled mob, I think this is only used by mechs?
-	var/last_turn = 0
 	///Move delay of controlled mob, any keypresses inside this period will persist until the next proper move
 	var/move_delay = 0
 	///The visual delay to use for the current client.Move(), mostly used for making a client based move look like it came from some other slower source
@@ -133,8 +131,6 @@
 	///world.timeofday they connected
 	var/connection_timeofday
 
-	///If the client is currently in player preferences
-	var/inprefs = FALSE
 	///Used for limiting the rate of topic sends by the client to avoid abuse
 	var/list/topiclimiter
 	///Used for limiting the rate of clicks sends by the client to avoid abuse