- Closes https://github.com/enso-org/cloud-v2/issues/619
- Async execution controls
# Important Notes
There is no design for this, as such, implementation details use placeholder designs.
- The context menu uses a play icon. An icon similar in style to the "copy" icon *may* work to represent "run in background", but it may be difficult to visually represent that it is being run in the background, without obstructing it with a foreground window
- The icon for projects being run in the background have a green tint, to distinguish them from projects that will be (or are currently) opened in the editor.
- this will ***almost certainly*** need to be replaced with a proper design
- This *may* also make sense for the local backend, *however* as I don't know whether there is a way to access the completion progress of execution from the PM API, local backend support is currently *not* implemented in this PR.
- On a related note: as far as I am aware, there is also no such endpoint for the cloud backend. However, support for async execution was recently added, so I am adding the basic functionality corresponding to the `executeAsync` project state.
- Whether a project is being run in the background is currently lost on refresh. This is because the async execution state is currently not sent by the backend.
- Placeholder shortcuts have been added (Shift+Enter - Cmd+Enter is already taken by the "share" action, and shift+double click). These are totally optional, and can easily be removed.
