Support for Raspberry Pi

[bdlukaa]

Add support for Embedded Environments.

• [x] Video rendering support (#194) Video is the core part of the application. We must ensure the video rendering software is stable enough to release it.
• [x] Adapt the app for embedded devices (#199) Some functionalities are not available in an embedded environment, or have to be written from scratch.
• [x] Adapt the user interface The embedded user interface should be similar to the tablet's.
  • [x] All panels and sidebars compacted by default
  • [x] Left navigation should be used over top navigation

Additional context

• https://github.com/ardera/flutter-pi