API Endpoint for getting generic contact data

[jkuester]

Is your feature request related to a problem? Please describe.
Based on this discussion we should add a api/vi/contact endpoint (in addition to person and place) that will return return generic contact data (given the identifier for either a person or a place).

There are a number of situations in the CHT data model where one might have a contact identifier, but not know what type of contact it is associated with. (E.g. a report can be associated with a contact, but there is no guarantee if the contact is a person or a place).

Describe the solution you'd like
The api/vi/contact endpoint should support returning the full data for the person/place (implemented via cht-datasource) but under the generic Contact interface.

In cht-datasource we should move the Contact interface into a v1 namespace since it will be exposed as a first-class data type. We should also look at exporting some type assertion helper functions to confirm if a Contact is a Person or a Place.

Describe alternatives you've considered

• Just not supporting getting generic contacts and trying to update the various places in the data-model to always know the type.
• Add an endpoint for just getting the type of a contact (so you knew whether to get the entity from the person/place endpoint).