Update /cdns/{{name}}/snapshot to use data from new interfaces tables

[ocket8888]

I'm submitting a ...

• new feature / enhancement request

Description

The /cdns/{{name}}/snapshot endpoint need to be updated to utilize data from the new tables added by whatever PR resolves #4611.

This depends on #4611

Traffic Control components affected ...

• Traffic Ops client (Go)

Acceptance Criteria

• /cdns/{{name}}/snapshot in API 1.x AND API 2.x:
  • Provides the proper data in representations of cache servers as outlined in the blueprint for the GET method
• Any associated unit and/or client/API integration tests all pass.

See the Additional Server Interfaces blueprint for details.