FR: remote set-url

[BatmanAoD]

Is your feature request related to a problem? Please describe.

Git provides git remote set-url to change the URL of a remote without changing any tracking information. This is useful when a repository location changes or when you need to change the URL schema (e.g. from https to ssh).

Describe the solution you'd like

A jj command that corresponds exactly to git remote set-url; presumably it would be something like jj git remote set-url or jj git remote change-url.

Describe alternatives you've considered

For now, I just use the git remote set-url command. This only works with colocated repos.