Shared transport session pool to allow multi-agent deployments with socket dock #36
Description
As a continuation of #29. This PR added support for SocketDock, but assumes there's only one agent instance. If multiple instances of the same mediator agent are active, delivery of messages might not work as expected (as not all agents are aware of the open transport sessions).
Relevant code: https://github.com/openwallet-foundation/credo-ts/blob/main/packages/core/src/agent/TransportService.ts#L17