unit tests needed for RotatedSPOs

As #2345, RotatedSPOs is gaining functionality but we need unit tests.
I think currently the LCAO + rotation is in production and thus we need a unit test to cover this.
@spinedaflores could you make one?
test_MO.cpp was for LCAO and we can create test_RotatedSPOs_LCAO.cpp.
Evaluation functions for energy and derivatives should be included.

Start by reading test_MO.cpp and the RotatedSPOs LCAO and rotation implementation referenced in the issue. Add the proposed test_RotatedSPOs_LCAO.cpp coverage for energy and derivative evaluation, and verify that the unit tests pass for the production LCAO-plus-rotation path.

Written by the indexing model from the issue text.