[mod] unified processing of the reference vector modes with OTR_TRACKING_REF_ORIENT
requested to merge 109-harmonize-head-and-orientation-tracking-refvec-review into 109-harmonize-head-and-orientation-tracking
- solves the issue that alpha did not get reset when switching from the ref-rotation modes to the ref-vec modes
- simplifies the otr processing function
Related to #109