Task modules cannot be imported

[mhvk]

From https://github.com/mhvk/baseband-tasks/issues/242

In [32]: import baseband.tasks.generators
---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
~/python/test_chime_sideband.py in <module>
----> 1 import baseband.tasks.generators

ModuleNotFoundError: No module named 'baseband.tasks.generators'

Oddly, tab expansion does work for this...

EDIT: the problem is that module-level __getattr__ is not recognized by import. What does work is from baseband.tasks import generators, but this is often not what one wants. It seems that this needs a fix in baseband.tasks.__init__, to at least get the modules in the namespace (but perhaps not all their parts; not sure if that's worth it).