BCF viewer stores viewpoints with clipping planes in a way, that direction of clipping plane is the vector pointing towards the `visible` area. But, in BCFv3 and in revit, the direction vector points towards the `invisible` area. To standardize the data, we want to store data always in the BCFv3 convention.

TODO:

* loading and saving of viewpoints in bcf viewer must work with defined direction vector
* Begin of the deletion (optional)End of the deletion add migration strategy for legacy data