与托管引用对象（动态）完整类型字符串的值对应的字符串。
Contains a valid value when propertyType is SerializedPropertyType.ManagedReference. This property is Read Only (you cannot write to it).
The full type name string returned has the following format: "[assembly-name] [namespace.][parent-class-names][classname]" where:
- [assembly-name] is the name of the assembly that contains the target type
- [namespace.] is an optional (if empty) namespace followed by a '.'
- [parent-class-names] is a '/' separated list of optional parent class names (in the case of nested class definitions)
- [classname] is the actual dynamic type name of the managed object class.
'null' references return an empty type string.
Additional resources: propertyType, SerializedPropertyType.ManagedReference.