Remove old and unused project settings, update various demos for 4.2 (#1024)

- Move all demo projects that don't require Forward+/Mobile-only features
  to the Compatibility rendering method. This improves performance significantly
  on low-end devices and ensures visuals are identical to a web export
  of the demo.
- Set deadzone on all inputs to 0.2 for better gamepad usability.
- Remove reliance on `default_env.tres` to use built-in Environment
  resources in the main scene instead (which follows the preview environment
  workflow).
- Remove notices pointing to GDNative or VisualScript, since both were
  removed in 4.0.
- Various bug fixes and usability tweaks to 10+ demos.

networking/websocket_minimal/README.md

@@ -1,9 +1,9 @@
 # WebSocket Minimal
 
-This is a minimal sample of connecting two peers to each other using websockets.
+This is a minimal sample of connecting two peers to each other using WebSockets.
 
 Language: GDScript
 
-Renderer: Forward+
+Renderer: Compatibility
 
 Check out this demo on the asset library: https://godotengine.org/asset-library/asset/539

networking/websocket_minimal/project.godot

@@ -11,7 +11,7 @@ config_version=5
 [application]
 
 config/name="WebSocket Minimal Demo"
-config/description="This is a minimal sample of connecting two peers to each other using websockets."
+config/description="This is a minimal sample of connecting two peers to each other using WebSockets."
 config/tags=PackedStringArray("demo", "network", "official")
 run/main_scene="res://Main.tscn"
 config/features=PackedStringArray("4.2")
@@ -20,9 +20,10 @@ config/features=PackedStringArray("4.2")
 
 window/size/viewport_width=600
 window/size/viewport_height=300
+window/stretch/mode="canvas_items"
+window/stretch/aspect="expand"
 
 [rendering]
 
-quality/driver/driver_name="GLES2"
-vram_compression/import_etc=true
-vram_compression/import_etc2=false
+renderer/rendering_method="gl_compatibility"
+renderer/rendering_method.mobile="gl_compatibility"