Improvements for the aura floor height detection
Closes #285 (closed).
This merge request introduces multiple raycasts to find the floor height around the user. Instead of just one raycast which might yield incorrect results, e.g. if the user is sitting on a chair, six raycasts are evenly distributed around the user.
The solution first looks for the minimum value. To accomodate for slightly sloped floors, the floor height is then determined as the maximum value that was found within a 20cm zone above the minimum value.