BPHY8: Add option to save all muons in DAOD

This merge request adds the option to save all (original and calibrated) muons to the DAOD. This option may be enabled by the statement BPHY8_KeepAllMuonsPtCut=0 in the preExec of a p-tag. It's intentional that the default for BPHY8 is kept as is in order to not overly enlarge regularly produced DAODs. The new option is needed for some specific special studies.

Reviewers please note that the file BPHY8.py is quite long due to important comments which need to be kept. Please ignore a corresponding warning by the ATLAS robot.

cc: @abarton