Multiple "scenes" for screen resize (#270)

## Link to GitHub Issue, if one exists
Fixes #263 

## Description of change
Add "scenes" to screen resize.

* UI changes - F11 menu now has a "scene switcher" for `Scene 1/2/3/4`.
Clean up other UI bits.
* Add hotkeys for `Screen Resize Scene 1`, `Screen Resize 2`, and so on.
* Detect hot key and trigger resizes.
* Add additional objects to screen_resize.json for saving and loading
the new scene settings.
* Existing screen resize data is backwards compatible (can be
loaded/saved to JSON), and is treated as `Scene 1`.
* Add API endpoint for `Resize`, allow toggling resize on/off, switching
active scene
* Add Python wrapper. Did not bother with the other wrappers (Dart, C++,
etc)...

## Compiling
🥇 

## Testing
Still testing, but seems to work fine for TDJ.

src/spice2x/README.md

@@ -246,6 +246,12 @@ which also means that your hex edits are applicable directly.
 - info()
   - returns information about the serial LCD controller some games use
 
+#### Resize
+- image_resize_enable(enable: bool)
+  - enables or disables image resize state
+- image_resize_set_scene(scene: int)
+  - sets the active scene for image resize state; set to 0 to disable resize
+
 ## License
 Unless otherwise noted, all files are licensed under the GPLv3.
 See the LICENSE file for the full license text.