Plugin package management support

[James-Mart]

Currently, when we write plugins, it is necessary to link to the component wit interfaces directly on disk in order to generate bindings. cargo-component and other standard component tooling increasingly have the ability to use component registries instead.

If we want standard component tooling to be able to read plugins directly from a psibase deployment, then psibase will need to be OCI distribution spec compliant.

It's not yet clear to me if the component packages themselves will also need to be OCI image format spec compliant.