Public API refactor #908
Description
We would like to carry a Newton-style refactoring of the public API so it's clearer what is part of the Warp public API and what is an internal interface. See newton-physics/newton#519 as an example.
The difference is that we want to do this using a two-minor/major-version deprecation policy, so there will be a period where the existing imports of non-public modules keeps working, but with a DeprecationWarning.
Example:
warp.types.type_length() is a handy function that some users might be using by doing an import warp.types, but it's not in our public API. Doing an warp.types.type_length() will still work during the transition period, but with a DeprecationWarning. We also want to promote such generally useful functions to the public API.