Skip processing

[tieneupin]

This PR is built on top of PR #21, so merging this will cover both PRs.

• If no recipes are present in the machine configuration, the frontend should not prompt users to provide processing parameters.
• The call to set up the multigrid watcher needs to be awaited in order to avoid a race condition where the request to start the watcher is sent before it's fully set.
• Enabled the "Skip Processing" button that will disable processing for this session. This coincides with PR (#590) in the main Murfey repository.