Converts A && A.B into A?.B (#54342)

Implements the ?. operator, replacing code like A && A.B with A?.B

BYOND Ref:
When reading A?.B, it's equivalent to A && A.B except that A is only evaluated once, even if it's a complex expression like a proc call.

code/game/objects/structures/fireaxe.dm

@@ -51,7 +51,7 @@
 	else if(open || broken)
 		if(istype(I, /obj/item/fireaxe) && !fireaxe)
 			var/obj/item/fireaxe/F = I
-			if(F && F.wielded)
+			if(F?.wielded)
 				to_chat(user, "<span class='warning'>Unwield the [F.name] first.</span>")
 				return
 			if(!user.transferItemToLoc(F, src))