[FIX] Test data caching and unzipping

[AlexVCaron]

There is problems currently when test data starts to download but then an error occurs in the code or the workflow. It was hard to implement in the current form of the load_test_data workflow. I revamped the structure that handled the cache, using CRUD operations (create, read, update, delete), so every corner cases are correctly handled by implementation. There are try/catch everywhere to make sure that the cache doesn't get polluted, so we should be ok from now on.

For reference, it's kind of what I implemented in Scilpy for fetch_data, but better 😛

Also, in addition :

• Added pdiff and configured the devcontainer to print the differences in nf-test results better

Bug category

• Critical (some functionalities is not working at all)
• Major (something is not working as expected)
• Minor (something but could be improved)
• Trivial (documentation needs correcting and other non-functional issues)

Describe the bug

Bad data gets stuck in cache.

Steps to reproduce the bug

1. Delete the cache (in ~/.local/share/nf-test-archives)
2. Start a test and kill it fast. Then again, a few time. You'll corrupt the cache eventually doing this.
3. Start a test and let it run. It should error out. If not, sart again at 2.

[AlexVCaron]

@gagnonanthony this should resolve the problems with preproc_t1 leading to errors. I'll update you on that once it works on #82