Remove __init__.py with no meaningful python scripts in the directory

Several places had:

atlas_install_python_modules( python/*.py )

and nothing but a single __init__.py in the directory. Removed these.

There were a few edge cases which involve auto-generated python, so I've left these.

MuonSpectrometer/MuonCablings/MuonMDT_Cabling/python/__init__.py

-# Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
-
-# template __init__.py defined in the GaudiPolicy package.
-