Fixes Only One Accessory Equipped at Spawn & in Character Preview (#7727)

Ported from https://github.com/Aurorastation/Aurora.3/pull/10205, credit to fernerr

Now you can see all the accessories (within standard equipping logic) you've selected in the character preview.

Addditionally, these accessories will now all be equipped when you spawn instead of filling your backpack unless it's actually necessary.

code/modules/mob/new_player/preferences_setup.dm

@@ -220,7 +220,7 @@
 				break
 
 	if((equip_preview_mob & EQUIP_PREVIEW_LOADOUT) && !(previewJob && (equip_preview_mob & EQUIP_PREVIEW_JOB) && (previewJob.type == /datum/job/ai || previewJob.type == /datum/job/cyborg)))
-		var/list/equipped_slots = list() //If more than one item takes the same slot only spawn the first
+		var/list/equipped_slots = list()
 		for(var/thing in gear)
 			var/datum/gear/G = gear_datums[thing]
 			if(G)
@@ -243,7 +243,8 @@
 				if(G.slot && !(G.slot in equipped_slots))
 					var/metadata = gear[G.display_name]
 					if(mannequin.equip_to_slot_or_del(G.spawn_item(mannequin, metadata), G.slot))
-						equipped_slots += G.slot
+						if(G.slot != slot_tie)
+							equipped_slots += G.slot
 
 	if((equip_preview_mob & EQUIP_PREVIEW_JOB) && previewJob)
 		mannequin.job = previewJob.title