Support iOS `UIKeyCommand` for Registering keyboard shortcuts (discoverability).

## Feature Request

### Plugin

Keyboard

### Description

It would be an awesome accessibility feature if we could tie in to `UIKeyCommand` (as a no-op), to register application keyboard shortcuts so that they appear in the iOS keyboard shortcut discoverability list:

https://www.hackingwithswift.com/example-code/uikit/how-to-use-uikeycommand-to-add-keyboard-shortcuts


### Platform(s)

iOS

### Preferred Solution

`Keyboard.registerKeyCommand(input: string, modifiers: string[], action: () => void, discoverabilityTitle: string);`

If no action is provided, this would delegate to the Dom/WebView keyboard event listener. If an action is provided, the action would be called, but it would allow us to add items to this list:

I don't think there is an equivalent on Android / Web, but it would be nice if there were.

### Alternatives

None. Show keyboard shortcuts in-app via custom UI implementation.

### Additional Context