GetFlatIcon improvements. (#86077)

## About The Pull Request
I've added an get_icon_dimensions() call to a place where `icon.Width()`
and `icon.Height()` are called twice each. get_icon_dimensions uses a
cache of values so follow-up getFlatIcon() calls with the same current
icon won't have it call`icon.Width()` or `icon.Height()` which aren't
exactly cheap procs iirc.

I've also removed two of the fairly expensive
`length(icon_states(icon(curicon, curstate, dir)))` checks, because all
icon states have NORTH, EAST and WEST directions except 1-dir
icon_states which are always facing SOUTH. That is, unless there is some
farfetched procgenned bullshit that's probably not even possible and
worth checking against. We'll see.

## Why It's Good For The Game
GetFlatIcon is a very expensive proc, every bit of improvement is worth
it.

## Changelog
N/A

code/__HELPERS/icons.dm

@@ -771,15 +771,20 @@ world
 
 	var/base_icon_dir //We'll use this to get the icon state to display if not null BUT NOT pass it to overlays as the dir we have
 
-	//Try to remove/optimize this section ASAP, CPU hog.
-	//Determines if there's directionals.
-	if(render_icon && curdir != SOUTH)
-		if (
-			!length(icon_states(icon(curicon, curstate, NORTH))) \
-			&& !length(icon_states(icon(curicon, curstate, EAST))) \
-			&& !length(icon_states(icon(curicon, curstate, WEST))) \
-		)
-			base_icon_dir = SOUTH
+	if(render_icon)
+		//Try to remove/optimize this section if you can, it's a CPU hog.
+		//Determines if there're directionals.
+		if (curdir != SOUTH)
+			// icon states either have 1, 4 or 8 dirs. We only have to check
+			// one of NORTH, EAST or WEST to know that this isn't a 1-dir icon_state since they just have SOUTH.
+			if(!length(icon_states(icon(curicon, curstate, NORTH))))
+				base_icon_dir = SOUTH
+
+		var/list/icon_dimensions = get_icon_dimensions(curicon)
+		var/icon_width = icon_dimensions["width"]
+		var/icon_height = icon_dimensions["height"]
+		if(icon_width != 32 || icon_height != 32)
+			flat.Scale(icon_width, icon_height)
 
 	if(!base_icon_dir)
 		base_icon_dir = curdir