Adds ctrl/cmd+s shortcut to whole application with a noop default

closes #4516
- shortcut for ctrl/cmd+s on application level
- shortens a syntax for any route that is using 'save' method, shortcuts object doesn't have to be defined at all, only the save action.
'esc' and 'enter' require dot notation, rather than keys.

```
shortcuts.esc = {action: 'closePopups', scope: 'all'};
shortcuts.enter = {action: 'confirmModal', scope: 'modal'};
shortcuts[ctrlOrCmd + '+s'] = {action: 'save', scope: 'all'};
```