Show space index when CtrlOrCommand is pressed down

### Your use case

#### What would you like to do?

To have the space index overlayed on top of the space icon on the left sidebar when `CtrlOrCommand` is pressed down.

#### Why would you like to do it?

When you have a lot of spaces it is really difficult to meaningfully use the `CtrlOrCommand+[space index]` keyboard shortcut

### Have you considered any alternatives?

No, this is what Slack does and it really helps to navigate between communities

### Additional context

It should probably be debounced and shown only after half a second so that it's not displayed when using keyboard shortcut like copy or paste