failsafe setup screen improvements

The GCS's ( Mission planner at least) generally have a screen especially for setting/testing failsafe... and I know people who never used it because it didn't make sense to them. it's a problem of making it easier and obvious to the users in the setup wizard.

my suggestion is to make it more interactive for the user/s , in the same way the accel cals, and gyro cals both ask the user "to X", and then provide GUI feedback that it's been "done", the failsafe should work the sme way.

Possible Example instructions to users, force them to follow by ticking boxes ( or detecting their action some other way) saying they’ve done each:
step 0: remove your props or secure your copter to allow motors to spin at speed without hazard.
step 1: turn off your TX now please and press enter
step 2: copter/firmware or gcs looks at modes and throttle, and complains if anything looks wacky. eg only allow loiter, or rtl, or land, and/or don’t allow a zero throttle in stabilise.
step 3: please test this: fly your copter at low altitude, and in a safe place with no hazards or people now, enter "loiter", and then and turn off your TX while flying. ( risk of crash if you got it wrong is better to occur now, and at a low alt, rather than later when u may be higher, and over uneven terrain)
step 4: save the fact that user has completed the "failsafe validated" , into a EPROM/FRAM firmware value via mavlink. - will need both gcs and firmware support to do this.
step 5: it would nice if there was a way to reset the "failsafe validated" parameter if somebody changes something relevant ( or even if any other settings are uploaded from the GCS ) - will need firmware support to do this.

Start by reviewing the failsafe setup wizard and the existing accelerometer and gyroscope calibration flows, which the issue identifies as interaction models. Done means guiding users through failsafe checks, validating the configuration, recording completion through GCS/firmware support via MAVLink, and resetting that state when relevant settings change.

Written by the indexing model from the issue text.