ekf2: allow wind dead-reckoning after manual position reset

[bresch]

Solved Problem

Wind dead-reckoning using sideslip and airspeed fusion isn't able to start if the airspeed data isn't consistent with the filter. Since the ekf is doing inertial dead-reckoning, the estimate is probably worse than the airspeed measurement and we should allow a velocity reset.

Solution

When doing inertial dead-reckoning, allow airspeed fusion to start and reset the velocity estimate using airspeed if the consistency check is failing.

Changelog Entry

For release notes:

Allow wind dead-reckoning after manual position reset
New parameter: -
Documentation: -