Adding two commands to the cargo remote-settings CLI, `dump-sync` and `dump-get`. This allows
to download a local dump of a set of collections, and keep it up to date with the remote version.
It's also possible to open a PR right away to update this file in the app-services repo.
`cargo remote-settings dump-sync --create-pr` will create a local branch and push it to the repo.
When trying to `get_records` from the component, it first checks if the database has some,
if not, it checks if the collection exists and takes it from the local file.