LMS-1870 interface refactored, test image viewer improved

.../openbis/dss/screening/server/DssServiceRpcScreening.java

.../dss/screening/shared/api/v1/IDssServiceRpcScreening.java

...ening/shared/api/v1/SingleDataSetIdentifierPredicate.java

...reening/client/api/v1/IScreeningOpenbisServiceFacade.java

...d/openbis/plugin/screening/client/api/v1/ImageViewer.java

...lugin/screening/client/api/v1/ScreeningClientApiTest.java

...creening/client/api/v1/ScreeningOpenbisServiceFacade.java

...eening/shared/api/v1/dto/DataSetCodeAndWellPositions.java

...openbis/plugin/screening/shared/api/v1/dto/ImageSize.java

...nbis/plugin/screening/shared/api/v1/dto/WellPosition.java

.../plugin/screening/shared/api/v1/dto/WellPositionTest.java