Use Tuist as a remote cache backend

You can now connect your workspace to a remote cache provider, with Tuist as the first supported backend. Add a cache_provider setting in your fabrik.toml (local, named, or direct Tuist config), authenticate with the new fabrik auth login <provider> and fabrik auth logout <provider> commands, and all existing commands that use the cache, including build, run, test, exec, cache, and deps, will read from and write to the configured remote while keeping the local cache in front. The credentials are stored under your XDG config directory.