We currently watch for changes in .rubocop.yml from the extension and simply restart the server in case the configuration was modified.

We should migrate the file watching so that it's initiated from the server, making it available in other editors too. Furthermore, we don't need to restart the server, but rather just re-initialize the RuboCop runner object to use the new configs.

Implementation

1. We need to send another request for file watching like this one, but instead requesting to watch the .rubocop.yml file.
2. When we receive the notification that a file has been modified, we need to add a specific check for .rubocop.yml here
3. We need to somehow update the configurations used by the RuboCop runner, which are initialized here. Alternatively, if there's no way to reconfigure the same runner instance, we might be able to re-initialize the singleton, which will do the right thing