refactor: rewrite backgrounds section with repeated style (#4112)

Ref #1536
#3399

Switched to new style engine and repeated style component for
backgrounds section. A lot of utilities are replaced with more generic
solution.
<img width="251" alt="Screenshot 2024-09-12 at 10 23 07"
src="https://github.com/user-attachments/assets/75dcff67-4754-4a6b-98e8-760d1efa58e6">

Author: TrySound

apps/builder/app/builder/features/style-panel/sections/backgrounds/background-content.tsx

@@ -11,7 +11,7 @@ import {
   RepeatRowIcon,
   CrossSmallIcon,
 } from "@webstudio-is/icons";
-import { StyleValue, toValue } from "@webstudio-is/css-engine";
+import { type StyleValue, toValue } from "@webstudio-is/css-engine";
 import {
   theme,
   Flex,