Splits the control scheme into separate schemes for the side buttons and touchwheel, allowing them to be configured independently of each other. At least one input must be used for navigation, and there are guards to prevent locking oneself out of any input. If the input scheme is invalid, a pop up will show alerting the user.

Different behaviours can be bound to the side buttons for when the device is locked or unlocked. This PR also adds a mode for these buttons that controls media playback (prev/next on up/down, pressing both buttons toggles play/pause).

There are some changes to the way inputs handle locking. Rather than the input devices tracking the current locked mode, different input devices are created on lock depending on the mode that is configured.

Reviewed-on: https://codeberg.org/cool-tech-zone/tangara-fw/pulls/264
Co-authored-by: ailurux <ailurux@noreply.codeberg.org>
Co-committed-by: ailurux <ailurux@noreply.codeberg.org>

Implemented for both the wheel and d-pad input methods.

- Themes can be loaded from disk and built-in
- Themes can be selected in a new themes menu of the settings screen
- Some touch-ups to existing themes
- The saved theme is persisted in nvs

Reviewed-on: https://codeberg.org/cool-tech-zone/tangara-fw/pulls/87
Reviewed-by: cooljqln <cooljqln@noreply.codeberg.org>
Co-authored-by: ailurux <ailuruxx@gmail.com>
Co-committed-by: ailurux <ailuruxx@gmail.com>

This saves a second or two from bootup; AFAICT this *mostly* reclaims
the dynamic fonts boot time regression.

Includes no longer blocking the main menu on an sd card being inserted!!