Integrate Inbox with Conversations + API

[jazzz]

Problem

Ensure that the API can access Inbox functions for creating bundles, creating conversations from bundles, and handling inbound messages. This Task is complete when a PrivateV1 convo can be initialized from the API using bundles generated from another client.

Context

PR #13 provides functionality into Inbox, however it still needs to be integrated with the FFI api to be accessible

[jazzz]

This #25 the inbox flow can be executed from FFI.

There is an example of this here