When a state stops to be estimated it becomes a "consider state". Its value and variance are frozen but its covariance with other states continue to evolve normally.
- removes conservative accel bias variance limiting
- force symmetry is skipped after fusion of NED vel/pos (a direct measurement)
---------
Co-authored-by: bresch <brescianimathieu@gmail.com>
fix test by reducing the distance to the new origin: the maximum size of
the local position origin is a cube of 1e6m. If the origin is moved
further than this, the state is clipped to that maximum value