Import Debian changes 3.35.3-1ubuntu1

orca (3.35.3-1ubuntu1) focal; urgency=medium

  * Update and resynchronize on Debian, remaining Ubuntu changes
  * debian/patches/unity-a11y.patch: add hacks to better work with Unity
  * debian/control.in: build with gstreamer now but lower the python3-gst-1.0
    recommends to suggests while that component is still in universe
  * Removed Ubuntu delta
  * debian/patches/0001-Add-GSettings-backend-to-Orca.patch:
      remove the gsettings backend, it's unmaintained and buggy
      (lp: #1783641)