use constructor injection and MockitoBean

...ebased/formsolutions/FormSolutionsEngineBasedAdapter.java

.../enginebased/formsolutions/FormSolutionsHeaderMapper.java

...d/formsolutions/FormSolutionsAntragstellerMapperTest.java

.../formsolutions/FormSolutionsEngineBasedAdapterITCase.java

...ed/formsolutions/FormSolutionsEngineBasedAdapterTest.java

...inebased/formsolutions/FormSolutionsHeaderMapperTest.java

...nebased/formsolutions/FormSolutionsHeaderTestFactory.java

...ginebased/formsolutions/FormSolutionsPanelMapperTest.java

.../enginebased/formsolutions/IdentifierValueParserTest.java