This MR is the first step towards tackling the locking issues which are plaguing the firmware right now. Commit 82fe0cd7 introduces a new mutex API and the rest of the commits port a few select mutex-uses to it. Those are:
- Lifecycle/Core 1 mutex
- Sensor streams
- API dispatcher lock
- FAT filesystem
The rationale behind the new mutex design is detailed in the docs added as part of this MR: mutex.rst. The API can be found in mutex.h.
Cc: @schneider