Test Function for Sketched Selectors

**Please describe your motivation for this feature request**
Currently the QRCP and LUPP selectors have the same sets of tests. This is redundant code that should be removed.

**Describe the solution you'd like**
Write a function to perform these tests similar to the one written for compressor/array multiplication.

**Describe alternatives you've considered**
Could leave code the way it is.

