Transition plan: Replace this repo with bedrock-vc-delivery once existing services are transitioned

[dlongley]

The bedrock-vc-delivery repo and package is expected to handle the functionality provided by this module but as a wholly separate service, whereas this module concurrently must be installed into another application / or "coordinator" (VC-API terminology) software.

Once any critical applications that depend on this module are updated to use bedrock-vc-delivery, this repo should be renamed, potentially released under a different name if any maintenance is still required, and archived. The bedrock-vc-delivery module should be renamed to bedrock-vc-exchanger and released as a new major version.