Fix setTimePoint calls by the BDV window

[maarzt]

Synchronized the Blender view with a BDV view in Mastodon leads to unintended jump of the timepoint whenever a spot is selected in Blender.

Selecting the spot in Blender triggers a navigate to event. The spot is not necessarily at the currently active timepoint (fix this).
Also BDV fires wrong setTimepoint events which leads to an unintended timepoint.