python linsys solver improvements

[bamos]

• [ ] Add support for other precision.
• [ ] Decide if anything else should be passed back up to Python.
• [x] Add normalization.
• [ ] Add some docs and a description somewhere.
• [ ] Add more checks to the functions passed in to make sure they are reasonable/take the correct number of arguments since otherwise errors coming from C calling back into Python can be uninformative/unnecessarily long
• [ ] Add in standard normalization routines to the library users can call if they don't want to implement their own