Draft: Autogen: Fix Ninja uic incremental build & uic build folder leakage
This MR introduces a new policy about the usage of UI files. The primary purpose is to fix the incremental build issue with Ninja and get more control over the UI files. It also fixes the build folder leakage issue for UI files when using the new policy.
Fixes: #16776
Fixes: #25195
Fixes: #25436
Topic-rename: autogen-uic
Edited by Orkun Tokdemir