utils: formatting + PEP8 + PEP257

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
utils: fix for `dateutils.datetime.combine` method

* Adds the missing `time.second` into the constructor.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
utils: test `convert_datetext_to_datestruct`

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
utils: test `date.convert_datestruct_to_dategui`

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>