Reg source pipeline

[jmwample]

Issue

The delay on the client affords one liveness check but not two serially which is what is currently happening for registrations received over the decoy registration channel then shared over the registration API.

We need to reduce this to one liveness check.

Solution

To address this This pull request makes changes to the protobuf structs used to wrap the ClientToStation message.

Merge ClientToStation Wrappers

The first change is to merge ZMQPayload and ClientToAPI into one protobuf struct called C2SWrapper. This can now be used for both purposes and allows for extra information to be shared ecternal to the actual ClientToStation message (e.g. source and decoy addresses which the application and registration management system would otherwise not have access to).

Add Prescanned flag

I have chosen to add a Prescannedfield to the RegistrationFlags internal to the ClientToStation message. This is the flag that is relied on to indicate if a registration shared over the API has been scanned already or not. The Registration API does NOT interfere with this flag. At the same time I am leaving the DetectorPrescan Registration source so that we can tell how effective registration sharing is and track metrics about it independently of the decoy registration channel.

Notes

Because the Prescanned flag is internal to the ClientToStation message and the Registration API makes no checks to validate the source of registrations or differentiate decoy registrations shared over the API from client registrations submitted through the API clients could set the Prescanned flag on their own. This is not a big concern at this time because the liveness scans exist to facilitate connections, and bypassing the liveness scan only means that a live phantom will break the connection phase for the client.

see also the conjure repo PR associated with this