- <cfloat> isn't available in the NuttX c++ library

This is a step towards isolating time from the system.

Yaw airmode w/o arming switch is most likely not what you want and will
lead to surprising results.

- partially addresses #11017

Fixes these invalid format strings:
- A `%d` for a pointer (replaced it by `%p`)
- A 0x%08x (and a 0x%0x8!) for a pointer (replaced by %p)
- 2 cases of `%d` for a `ssize_t` (replaced it by `%zi`)
- 1 case of a %u for an `int` (replaced by %i)
- 3 cases of %d for a `long` (replaced by %ld)
- 19 cases of `%d`, `%i`, `%u` or `%lu` for a `size_t` (replaced it by `%zu`)
- An unused formatting argument (removed it)
- A missing `%d` (added it)
- A missing `%s` (added it)
- 2 cases of `%llu` for a `uint64_t` (replaced it by `"%" PRIu64`)
- 6 cases of giving a string directly as format string (replaced it by `("%s", string)`)
- 2 cases of %*-s, which should probably have been %-*s.
  (Looks like NuttX accepts (the invalid) %*-s, but other platforms don't.)
- A %04x for a `uint32_t` (replaced by "%04" PRIx32)

To my knowledge this hil transition function is not used anymore,
however, it makes sending the DO_SET_MODE command unnecessarily complex.
In my opinion the DO_SET_MODE command should only change the mode but
not other things like arming (already removed) and HITL state (this
commit).

Often times, I was seeing the error message "Set SYS_HITL to 1 and
reboot to enable HITL." when using QGC with a vehicle in HITL.

HITL is set via parameter which then has an impact in the startup script
where the CLI argument `-hil` is added to some of the commands that
require it (like commander as well).

This flag does not seem to be used anywhere.

after review comment request from @dagar. Thanks!

such that fractions of a second are configurable

 - #10359

Failure Detector - use bitmask field instead of boolean in vehicle_status msg (failure_detector_status) and instead of struct in class

Failure Detector - move "force_failsafe" flag inside circuit_breaker protection; remove PX4_WARN and send mavlink msg only once

- use pragma once guard in FailureDetector.hpp
- send Commander parent to ModuleParams and remove update_params() method
- simplify attitude checks
- FailureDetector::get_status() (previously named "get") is now a constant method that returns a constant reference

FailureDetector - New class, first working simple implementation. Outputs PX4_ERR messages if roll or pitch is exceeded.

It's now the same way as in the ARM logic further down.

A reason for using switch arming in the first place is that you cannot
accidentally disarm in-air with the sticks during acrobatic flights.

It also adds a low-throttle arming requirement for switch arming.

This changes the arming logic such that the preflight checks don't need
to be satisfied if arming happens < 5 seconds after the last disarming.
This allows to recover from accidental in-air disarming.

- this matches the logic in arming_state_transition()
- if Commander::preflight_check was run in armed state and the checks
  failed, disarming was not possible anymore
  (because disarming checks for condition_system_sensors_initialized).
  That is currently not the case, but the existing logic is way too fragile.

Alternative solution: check if armed in Preflight::preflightCheck, and
only transition to false if disarmed (but also respect the re-arming
grace period).