packaging: setup: reorg the per component directory

rename:
dwh/dwhconfig.py.in -> dwh/config.py.in
dwh/dwhconstants.py -> dwh/constants.py

Change-Id: Ifb0256b898650b6986608021c543fa6b5ac2fddc
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>