Fixed: phpdoc param hint
Fixed: creating ContentType needs some more minimal data

- for REST not to crash on server parser
- to catch correct InvalidArgumentException
Removed: deprecated method
Fixed: phpdoc typos
Fixed: phpdoc type hints
Added: typegroupByIdentifier and typeGroupAssign resource mapping
Implemented: loading ContentTypeGroup by identifier
Added: ContentTypeList/ContentType to force list array
Updated: make names and descriptions optional
Added: ContentTypeGroupList VO
Added: ContentTypeList and ContentTypeGroupRefList parsers
Implemented: getContentTypeGroups()
Updated: names and desciptions optional, wrap in ContentTypeDraft if status draft
Updated: allow translatable list to have empty translation text
Fixed: phpdoc typos and type hints
Added: ContentTypeCreateStruct and FieldDefinitionCreateStruct visitors
Implemented methods: createContentType, loadContentTypeGroupList, loadContentTypeByRemoteId, loadContentTypes, assignContentTypeGroup, unassignContentTypeGroup