Relay: Enhance client data store to support adding telemetry bundles that are extracted from a telemetry report

[rtamalin]

When a telemetry relay receives a telemetry report it needs to process it to extract the included telemetry bundles and store them in a client data store, so that they can subsequently included in telemetry reports submitted to the telemetry relay's upstream telemetry server.

To support this we will need to be able to add telemetry bundles directly to the client data store.