Python: Add support for setting geometry on an existing case

[magnesj]

replaceCase is supported based on a file name. Add similar functionality used to set all geometry of an existing case based on COORD/ZCORN/ACTNUM. Delete all existing properties on the grid case.

Add this function replace_corner_point_grid to the Python Case object.

Related functions

https://api.resinsight.org/en/main/api/rips.Project.html#rips.Project.create_corner_point_grid