Linux: use GTK sink for Wayland Bambu liveview (#13432)

* Use GTK sink for Wayland liveview

Keep native Wayland sessions on the GTK backend and use a GTK widget based GStreamer sink for Bambu liveview instead of the Wayland video overlay path, which can render black on NVIDIA/Hyprland.

Keep the existing wxMediaCtrl path for X11 and continue preferring software H.264 decoding while demoting GL and hardware decoder paths that caused liveview crashes.

* Narrow Linux liveview fix to native Wayland

* Tighten native Wayland liveview setup

* Tighten Wayland liveview teardown and rank setup

* Package GStreamer gtksink for Wayland liveview

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Co-authored-by: SoftFever <softfeverever@gmail.com>

scripts/flatpak/com.orcaslicer.OrcaSlicer.yml

@@ -35,12 +35,13 @@ finish-args:
 
 modules:
 
-  # JPEG codec for the liveview
+  # JPEG codec and GTK video sink (Wayland liveview) for the liveview
   - name: gst-plugins-good
     buildsystem: meson
     config-opts:
       - -Dauto_features=disabled
       - -Djpeg=enabled
+      - -Dgtk3=enabled
       - -Ddoc=disabled
       - -Dexamples=disabled
       - -Dtests=disabled