Databases should now be available on the CI, we do not rely on a zipped
db anymore.

Samples are not square cropped during data loading anymore due to recent
changes. Cropping is model-dependent.

[tests] Revamp tests for montgomery, shenzhen, indian, and tbx11k; Erase tests for outdated RS modules

[tests] Simplifies test database unpacking by moving code to a pytest initializer; Make tests more unaware of the test database