Disable autofocus checks when focus fails
Summary: The HFR and focus temperature thresholds are checked between exposures. But these checks are made active only once a focus has succeeded. So, it makes sense to stop doing these checks when focus failed or was aborted. Indeed, it means we do not have any focus temperature anymore.
Test plan:
- connect the focuser simulator
- check the temperature delta box
- perform autofocus
- perform a second autofocus and abort it
- create and start a sequence
- make sure the message "Warning: temperature delta check is selected but autofocus process was not started." is displayed
- increase the temperature in the focuser simulator
- verify that the autofocus is not triggered