test-ip-validation

This exists simply to help us feel confident that our client-side IP address and network validation in the web console considers the same inputs valid and invalid as our server-side Rust code. 100% parity is ideal, though not a hard requirement: it is probably ok if the two codebases disagree on a few edge-case inputs that users are very unlikely to actually want. It's better for the client-side validation to be more permissive than to be too restrictive, i.e., better to allow the occasional bad input to hit the server and get rejected there than to disallow the occasional good input and force the user to use the CLI.