PropertyTypes and PropertyGroups are loaded as part of the MemberType in one go.
MemberTypeRepository uses the same approach as the ContentTypeRepository and MediaTypeRepository for saving/updating.
Refactoring how the 9-PropertyType convention is handled.
Refactoring the sql query and the dtos to use the PropertyType as Primary and Property as secondary as a Property might be empty for a defined type.
Adding labels to the conventional Member PropertyType aliases.
