Normalize file names

[patientzero]

• As a researcher I need nomalized File Names to properly differentiate between collected data and to reliably check synchronization status.

Use the same naming schema for all exercise types.
User proper filename separators between all differentiating pieces of information encoded in filename,
e.g.
PatientID_Severity_Tapping.csv

[jcvasquezc]

The naming should contain the date when the exeercise was performed

PatientID_Exercise_date.csv

For instance

001PD_200719_Taping1.csv, or something similar

[AKuederle]

Currently the filename is localised! We need to change that!