[LMS-816],[LMS-834] check mandatory properties, modify external data

...generic/server/business/bo/EntityPropertiesConverter.java

...cisd/openbis/generic/server/business/bo/ExperimentBO.java

...sd/openbis/generic/server/business/bo/ExternalDataBO.java

...eneric/server/business/bo/IEntityPropertiesConverter.java

...x/cisd/openbis/generic/server/business/bo/MaterialBO.java

...isd/openbis/generic/server/business/bo/MaterialTable.java

...msx/cisd/openbis/generic/server/business/bo/SampleBO.java

.../cisd/openbis/generic/server/business/bo/SampleTable.java

...ystemsx/cisd/openbis/generic/shared/dto/ExternalData.java

...emsx/cisd/openbis/generic/shared/dto/ExtractableData.java

...systemsx/cisd/openbis/generic/shared/dto/NewProperty.java

...ric/server/business/bo/EntityPropertiesConverterTest.java

.../openbis/generic/server/business/bo/ExperimentBOTest.java

...penbis/generic/server/business/bo/ExternalDataBOTest.java

...openbis/generic/server/business/bo/MaterialTableTest.java

...cisd/openbis/generic/server/business/bo/SampleBOTest.java