Pull request #289: Bugfix/VECTO-1741 xml schema for batterysystem with standard values

Merge in VECTO/vecto-dev from VECTO/mq_vecto-dev:bugfix/VECTO-1741-xml-schema-for-batterysystem-with-standard-values to develop

* commit '97d15d73':
  implement reading XML battery standard values, writing battery with standard values to VIF
  additional mockup tests for vehicles with standard values for battery system
  adding sample XML file for battery with standard values
  Bugfix in Schema 2.3: introduce xml type for battery system with standard values (Vehicle and VIF)