Deploy parachute if watchdog resets in flight

## Feature request

Now that we have the capability to detect and recover from a hung CPU, we can think about instrumenting automatic failsafes if it happens in flight, such as deploying the parachute. This is particularly important for Copter, since they don't otherwise have an effective way to recover from a reset in flight.

**Describe the solution you'd like**
Allow the user to configure automatic chute deployment upon in-flight IWD reset. Maybe a CHUTE_ parameter. I suppose the logic would look something like this:

1. Detect IWD reset while drone was armed (already implemented)
2. Make sure that it didn't happen during some kind of non-flight operation, like a motor test
3. Try to check that the drone was indeed flying (maybe just check altitude of saved state vs CHUTE_ALT_MIN)
4. Trigger parachute
- Must make sure this isn't inhibited by safety/armed state, etc.

**Platform**
[ ] All
[ ] AntennaTracker
[x] Copter
[x] Plane
[ ] Rover
[ ] Submarine

**Additional context**
- Tridge mentioned this possibility in #4702, but I don't see further discussion of it anywhere.
- Plane may have the ability to execute mission commands such as do_parachute after IWD reset (#12131)

Start by reading the existing in-flight IWD reset handling referenced in the issue, then compare the Plane mission-command and do_parachute behavior from #12131 with the discussion in #4702. Define how a configurable CHUTE_ setting, armed-state exclusions, saved altitude, and motor-test detection should interact for Copter and Plane; done means the behavior is specified and covered for both platforms.

Written by the indexing model from the issue text.