SW-43: fix logging setup and adding the averaging selection the time window instead of the number of samples

SW-43: fix avoid modification of the source dict while storing. Fixing iteration over the attribute and the values of the h5 dataset.

SW-43: renamed function process_holography_dataset to a more specific name preaverage_holography_dataset

The test data is big.  Really big.  Too big to store it in a
source code repository.  This poses the problem that the test
has to either download it or to rely on the data being in a
defined location that is always on and always accessible from
everywhere.  Both solutions don't work in all cases.

Bottom line:  we have to figure this out!  For the time being the
test will just fail when the data is not in the expected location.

SSB-42: change script name to include .py extension and cmake script to rename the file when it installs it