Added script to test that all .py scripts in the saltOptimization directory run, and updated ci workflow

A workflow for cloning the dependent repositories and running the tests using pytest.

Removed extraneous symlinks to thermochimia directories, and updated paths in the benchmark and calculation scripts

Need to resolve thermochimica_output path first otherwise the logic that's meant to generate the relative path to the desired output directory will fail

To stop the proliferation of filepaths (that only work on my system with my installation of thermochimica and mstdb-tp) that will ultimately have to be replaced by the end-user (i.e. with the path to their own install of thermochimica and mstdb-tp) all filepaths were made relative to two symlinks to the thermochimica and mstdb-tp directories in the root of the repository, then the only thing that must be changed is the symlink and all of the code in the repo should run without issue

Updated pseduo_binary_calculation function to take absolute paths for the output directory (which makes more sense anyways) and added some logic to automatically convert the absolute output path to a path relative to the thermochimica outputs directory so that the code will run without issue

Updated code so that it may be run from different directories without issue, also fixed incorrect path names in file IO parameters that were not updated when the fuelOptimization directory was updated to saltOptimization

Fixed several bugs/typos that were preventing higher order systems with close composition data from being applied

Made sure to include absolute value in uncertainty for quantities that may be negative (I believe my code was running into an issue and generating negative tp's). Added logic for taking the relevant higher order system directly from the database if the compositions are within a (user editable) tolerance, taken by default to be 0.025.This fixed the density prediction for FLiNaK and FLiBe, and now all plots are consistent with references.

Fixed processing of uncertainties and conversion from percent to fractional uncertainty. The error before was just neglecting the uncertainty in tp's and only accounting for the uncertainty of boiling/melting points

Finished RK density benchmarking, along with documentation. Still need to do benchmarking for other properties