ffi bindings for protocol crate

[amika-sq]

In order to be able to be consumed by a foreign language, bindings must be created for the tbDEX protocol.

We'll need to export all functionality of the protocol, as it's up to the consumer of the SDK to make business decisions related to the usage of Messages/Resources.

We should start this work only once there's a considerable amount of progress made on the protocol itself. We should also use findings from the web5-rs repo, as that will be exposed to foreign languages via ffi first.