this is branched off of `gen_schema_2`

_but_ there's an issue with `serde` being imported in both libraries.
I'd really like to have that not be the case.

Other changes...

- added the module name to the `Table` trait, could be better for errors
and messaging/debugging.

- figured out _something_ with forwarding external dependencies with
`$crate::Dep`

- `run_proxy!` macro can be used as _main_, so that means, (coolly),
that we don't need tokio to be included in the user's lib, all the stuff
with it not working was just a bad copypasta, and poor error messages
before.