New sofas added, need to be added to sheet_types.dm still

Backing up the .dmi changes and two comfy chairs.

code/game/objects/structures/beds_chairs/sofa.dm

@@ -0,0 +1,37 @@
+/obj/structure/chair/corp_sofa
+	name = "sofa"
+	desc = "Soft, cushy and cozy. These sofas reek of bland faceless corporatism, but they aren't old and ratty at least."
+	icon_state = "corp_sofamiddle"
+	icon = 'icons/obj/sofa.dmi'
+	buildstackamount = 1
+	var/mutable_appearance/armrest
+
+/obj/structure/chair/corp_sofa/Initialize()
+	armrest = mutable_appearance(icon, "[icon_state]_armrest", ABOVE_MOB_LAYER)
+	return ..()
+
+/obj/structure/chair/corp_sofa/post_buckle_mob(mob/living/M)
+	. = ..()
+	update_armrest()
+
+/obj/structure/chair/corp_sofa/proc/update_armrest()
+	if(has_buckled_mobs())
+		add_overlay(armrest)
+	else
+		cut_overlay(armrest)
+
+/obj/structure/chair/corp_sofa/post_unbuckle_mob()
+	. = ..()
+	update_armrest()
+
+/obj/structure/chair/corp_sofa/left
+	icon_state = "corp_sofaend_left"
+
+/obj/structure/chair/corp_sofa/right
+	icon_state = "corp_sofaend_right"
+
+/obj/structure/chair/corp_sofa/corner
+	icon_state = "corp_sofacorner"
+
+/obj/structure/chair/corp_sofa/corner/handle_layer() //only the armrest/back of this chair should cover the mob.
+	return