Various safety nets for flashing starting from bootloader mode

[algernon]

This does a few things in case Chrysalis arrives to the FirmwareUpdate screen while the keyboard is in bootloader mode:

• It will default to enabling factory reset (but can still be toggled off)
• It will display a warning message in place of the firmware version, explaining the dangers of flashing from bootloader mode, and recommending to try normal flashing if possible
• The Upload button will become "Upload anyway", and use the secondary color
• A new "Cancel and disconnect" button will be displayed (in primary color) to provide an easy way out

[algernon]

Ideally, that "Cancel and disconnect" button would be "Cancel and exit bootloader mode". But surfacing that functionality from the bowels of @api/flash/*Flasher is... difficult.

[chrysalis-pr-bot]

Build artifacts for this pull request are available!

:warning: These are not official builds!

The build artifacts are provided as-is, for testing and reviewing purposes. They contain code that has not been reviewed or audited by Chrysalis' developers. They are not endorsed by Keyboardio, they are not signed. Install and use them only if you know what you are doing.

• Windows:
  • Installer
  • Portable
• macOS:
  • zip
  • dmg
• Linux:
  • AppImage