This will make it easier for users who do not want to use the bindings

Standardized the output file and added constructors to recreate model from the output files

Make it easier to work with units and models in python

expose c++ class/functions to python

-Saves memory
-should allow for larger sis to get past MPI send

Made Model Nodes

Models now do not connect to the main value arrays so it will be easier to serialize in the future

used wrong variables.

limit the number of operations done

Works on initial test cases

Division/multiplcation nodes cant have division features/inverse

empyt unit check

a typo and test_value_ptr()/set_test_value() only redirects if _selected is false for feature node

typos when introducing the test set led to problems

Did them one after another, adding both here now

Refactored C++ SISSO code now running properly.

Further tests are needed to further debug, need to work on memory access and bringing in new features