When a Cloud Datum Stream is configured for a device, and the device is replaced over time, currently we can only add that new device to to the Datum Stream configuration such that SolarNetwork requests both devices when polling for datum. This is because the Datum Stream configuration represents "all time" and data could be requested for time ranges that have either the original device or the replaced device.

This leads to some inefficiency, as usually for a given query only once device is needed (because the two devices do not overlap in time). To be more efficient, if SolarNetwork knew the "operational date range" of a device, it could more intelligenty request just the needed information.

This ticket is to add support for that device-level "operational date range" metadata on Cloud Datum stream entities, and then for the stream to make use of that metadata when querying device-level data to avoid making requests for device data outside its operational date range.

Note that an operational date range can be open-ended, for example have no end date (for devices that are currently in operation) and that the absence of any operational date range metadata should be interpreted as operational for "all time".