Refactor field names of PersistencyResources to reflect that the fields cannot be null.

...neric/server/business/bo/common/DatabaseContextUtils.java

...enbis/generic/server/dataaccess/PersistencyResources.java

...dataaccess/db/AbstractGenericEntityWithPropertiesDAO.java

...generic/server/dataaccess/db/AuthorizationDAOFactory.java

...penbis/generic/server/dataaccess/db/EntityHistoryDAO.java

...s/generic/server/dataaccess/db/EntityPropertyTypeDAO.java