Blender Git Loki

Fix T64829: Active point of Curve objects is not displayed correctly

three issues here:
- when curves had multiple nurbs, the active vert is per nurb
[curve_create_edit_data_and_handles() wasnt taking that into account]
- code could go wrong when points where hidden
- upon selection, tag curve ID_RECALC_COPY_ON_WRITE for batch cache
update

Reviewers: brecht, fclem, sergey

Maniphest Tasks: T64829

Differential Revision: https://developer.blender.org/D4943