Discovery of service parameters

[johnandersen777]

Knowledge of SCITT's tree algorithm and parameters for that tree algorithm are required for a client to verify receipts. It seems like we need to have an endpoint to enable discovery of those parameters.

[johnandersen777]

Nevermind the client code just need to get the tree alg from the receipt.

[johnandersen777]

Related: #79 (comment)

[johnandersen777]

After discussion this weekend with Steven and Cedric we talked about needing an endpoint for service parameter discovery. This also appears necessary for federation.

[johnandersen777]

The document currently states:

The Transparency Service provides an endpoint that returns the Transparent Statement that describes its current configuration."

The Transparency Service records its configuration in the Append-Only Log using Transparent Statements with distinguished media type application/scitt-configuration.

From: https://github.com/ietf-wg-scitt/draft-ietf-scitt-architecture/blob/930a0cd38a92dd6079bda2ed3c675019ee9b0aa3/draft-ietf-scitt-architecture.md#configuration

Pining based on #126 discussion comments: @fournet, @SteveLasker: I read this to mean the endpoint is a subject/feed, what is that subject/feed? Is it the issuer did:web: combined with the mentioned media type? How should we register these so that they are discoverable in a consistent way?

[SteveLasker]

Queue to move to the SCRAPI repo