Restructure modules

[ricardoV94]

Description

We have very long modules with arbitrary names like tensor.basic vs tensor.extra_ops, and nlinalg vs slinalg. We should organize the modules by operator functionality. I would error on the side of having too many modules than too few. tensor.array_creation, linalg.solve, linalg.decomposition, ..., or even at the level of individual ops when they are complex enough.