Request: Update Julia tests, delete FactCheck, add IntervalContractors as new output dir

[miguelraz]

@oheim !

Thank you so much for the amazing response you gave this weekend - it helps us greatly!

I would like to make a few quality of life PRs for our testing infrastructure, but am not too sure where to poke around - perhaps you could help.

Our goals right now are

1. Delete the FactCheck testing library.
2. Make a new testing library that only generates the tests for the reverse methods, under a file called IntervalContractors, with all other presets being the same, except for an import of using IntervalContractors at the top.
3. Update some of the method names for the interval contractors - incoming PR update reverse method names for IntervalContractors.jl #13.

If you have some pointers on how to get that done, I would highly appreciate it.
Once again, thanks a lot!