Added an update ScenarioDefinition method and extracted the storage
mthods in all the RESTful service classes into a more general helper
class "ServiceStorageModul". All methods to store things can be accessed
in a static way.
Method to save are e.g. to update the AccountDetails accordingly or
furthermore store the correct 

Change-Id: Iafc822ad21a3d8aaad54ee135de21193951df6a7
Signed-off-by: d061465 <p.merkert@sap.com>