Misc. runtime fixes (#4545)

## About The Pull Request
No player-facing changes

This fixes a runtime in donator status code by making it return if there
is no prefs.parent
This fixes a runtime in emote code by making the code check if the user
is living so the variable isn't undefined
This fixes a runtime in Skyrat MODsuit code by making the code check if
there isn't a wearer

## Why It's Good For The Game
I fix

## Proof Of Testing

<details>
<summary>Screenshots/Videos</summary>

</details>

## Changelog

🆑 ReturnToZender
/🆑

modular_skyrat/modules/customization/modules/mob/living/carbon/human/MOD_sprite_accessories/mod_accessory_handler.dm

@@ -7,22 +7,22 @@
 		return
 
 	update_external_organs_modsuit_status(is_sealed && active)
-	wearer.update_body_parts(TRUE)
+	wearer?.update_body_parts(TRUE)
 
 /obj/item/mod/control/control_activation(is_on)
 	. = ..()
 	update_external_organs_modsuit_status(is_on)
-	wearer.update_body_parts(TRUE)
+	wearer?.update_body_parts(TRUE)
 
 /obj/item/mod/control/deploy(mob/user, obj/item/part, instant = FALSE)
 	. = ..()
 	update_external_organs_modsuit_status(active)
-	wearer.update_body_parts(TRUE)
+	wearer?.update_body_parts(TRUE)
 
 /obj/item/mod/control/retract(mob/user, obj/item/part, instant = FALSE)
 	. = ..()
 	update_external_organs_modsuit_status(FALSE)
-	wearer.update_body_parts(TRUE)
+	wearer?.update_body_parts(TRUE)
 
 /// Simple helper proc to force an update of the external organs appearance
 /// if necessary.

modular_skyrat/modules/emotes/code/emotes.dm

@@ -258,7 +258,7 @@
 				'modular_skyrat/modules/emotes/sound/emotes/clap4.ogg')
 
 /datum/emote/living/clap/can_run_emote(mob/living/carbon/user, status_check = TRUE , intentional)
-	if(user.usable_hands < 2)
+	if(!istype(user) || user.usable_hands < 2)
 		return FALSE
 	return ..()
 
@@ -276,7 +276,7 @@
 				'modular_zubbers/sound/emotes/claponce2.ogg')
 
 /datum/emote/living/clap1/can_run_emote(mob/living/carbon/user, status_check = TRUE , intentional)
-	if(user.usable_hands < 2)
+	if(!istype(user) || user.usable_hands < 2)
 		return FALSE
 	return ..()
 

modular_skyrat/modules/player_ranks/code/subsystem/player_ranks.dm

@@ -118,7 +118,7 @@ SUBSYSTEM_DEF(player_ranks)
  * * prefs - The preferences datum to check the donator_status eligibility.
  */
 /datum/controller/subsystem/player_ranks/proc/update_prefs_donator_status(datum/preferences/prefs)
-	if(!prefs)
+	if(!prefs || !prefs.parent)
 		return
 
 	prefs.unlock_content = !!prefs.parent.IsByondMember()