- set measurement of first sample to -1 to indicated that the data
is not valid

- give an estimate of the sensor variance based on the sensor resolution
and experiments

Signed-off-by: Roman <bapstroman@gmail.com>

Signed-off-by: Roman <bapstroman@gmail.com>

Signed-off-by: Roman <bapstroman@gmail.com>

Signed-off-by: Roman <bapstroman@gmail.com>

Signed-off-by: Roman <bapstroman@gmail.com>

Signed-off-by: Roman <bapstroman@gmail.com>

Move RC and DL failsafe actions handling from navigator to commander (credits to @AndreasAntener)
Separate manual kill switch handling via manual_lockdown to prevent override and release of software lockdown by RC switch

Other changes:
Add failsafe tune
Fix LED blinking for Pixracer
Return back support for rc inputs in simulator but now it is configurable via cmake

This disables the safety switch when Pixracer is configured. It does not change existing setups and it can be re-enabled after. This might be the more sensible default for a racing board.