Make skinning baseline behavior, restructure options into empty tabs

Skinning of both the ExtraActionBar and LayerPickerFrame buttons is no longer opt-in. Replaces the old single Skins tab and its toggles with two empty tabs, Extra Action Button and Instance Swap, for future per-frame settings.

Modules/ExtraActionBar.lua

@@ -129,10 +129,7 @@ local function TryHook()
 
 	if container and button then
 		SetupMover(container, button)
-
-		if E.private.CoA.extraActionBar then
-			SkinButton(button)
-		end
+		SkinButton(button)
 	end
 
 	return container ~= nil and button ~= nil

Modules/LayerPicker.lua

@@ -78,10 +78,7 @@ local function TryHook()
 	if button then
 		DisableDrag(button)
 		SetupMover(button)
-
-		if E.private.CoA.instance then
-			SkinButton(button)
-		end
+		SkinButton(button)
 	end
 
 	return button ~= nil