#50 added MetaObjectNodesStadtbildSerieSearchStatement and basic functionality
#50 added the functionality to search for image numbers in MetaObjectNodesStadtbildSerieSearchStatement
#50 make use of StringUtils.isNotBlank() instead of doing the check manually
#50 changed the method how the results are fetched and changed appendImageNumbers()
#50 added the possibilty to execute MetaObjectNodesStadtbildSerieSearchStatement in a preparation mode or in a normal mode
Merge branch 'feature/50-stadtbildserie-search' into dev