chores: Cherrypick patches on top of the latest app version

[OleksiyRudenko]

Patch-fixes of the following issues should be put on dev/main

• dev env: Add globalModulePaths in .postcss #34 postcss config (resolved by 74ba98c)
• framework/element: Add className property handling  #35 JSX className prop handling (resolved by 13576f7)
• framework/element: Add element's SELECTED, MULTIPLE, REQUIRED attributes handling #36 SELECTED, MULTIPLE, REQUIRED attributes handling (pending blocker)