The trust level of the PersonaStore for linking.
Each PersonaStore is assigned a trust level by the IndividualAggregator, designating whether to trust the properties of its Personas for linking to produce Individuals.
This value may change throughout the life of the PersonaStore.
The trust level may be queried by clients, but must not be set by them. The setter for this property is for libfolks internal use only.
0.1.13