Fix martin-ui crate packaging

[nyurik]

STATUS: this PR can use some help from other folks - it deals with NPM integration, which turns out is not working as intended... :(

The martin-ui dir must be part of the martin package, otherwise it does not get included in the cargo publish -p martin. We could also do it with a symlink from inside the /martin dir, but that gets a bit confusing - easier to just keep ui inside martin itself, as it is not used anywhere outside of that crate.

In order to prevent these bugs in the future, we might want to run cargo +nightly publish --workspace -Z package-workspace --dry-run as part of some CI -- this will take into account that some crates depend on the other, and that some/all of them have not been published yet

TODO

• modify martin/build.rs to install node files inside the standard build dir. Current dry run shows this error:

error: failed to verify package tarball

Caused by:
  Source directory was modified by build.rs during cargo publish. Build scripts should not modify anything outside of OUT_DIR.
  Added: <...>/martin/target/package/martin-0.15.0/martin-ui/dist
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/_
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/_/assets
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/_/assets/favicon.ico
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/_/assets/index-Cu-91x5d.js
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/_/assets/index-DZmjP79K.css
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/_/assets/logo-BlOKpv3a.png
  	<...>/martin/target/package/martin-0.15.0/martin-ui/dist/index.html
  	<...>/martin/target/package/martin-0.15.0/martin-ui/node_modules
  	           (and many files in this dir)

  To proceed despite this, pass the `--no-verify` flag.

I am not sure we should use --no-verify

fixes #1667

[nyurik]

cc: @paigewilliams - do you know how to best solve the TODO?