Make it easier to use already known hotkeys for users coming from popular operating systems

### Problem

I grew up using MS Windows most of the times. So most of the hotkeys that I can remember without any thinking are for example:
"Super" key for app menu
"Super + E" for opening file browser
and so on.

In elementary, key bindings for such actions are differ a lot.

### Proposal

Have some keymap profiles available for selection on a new page within the onboarding app with 3 default options as radio buttons and change the key bindings and the key shortcuts overview dialog accordingly when the user selects one of these actions.

The options should be
* elementaryOS Shortcuts
* Windows Style Shortcuts
* Mac Style Shortcuts

Maybe there are some more OS or distros I am missing here. Can't really remember whether vanilla Ubuntu's shortcuts differ a lot from MS Windows. If that is the case, it should also be added as an option. Same for other popular distros (Linux Mint? Fedora?, ...?)

### Prior Art (Optional)

_No response_

Start by reviewing the onboarding app, the existing key-binding definitions, and the shortcut overview dialog mentioned in the proposal. Clarify the supported operating-system profiles and their bindings; done means a user can select a profile and see the corresponding bindings and shortcut overview consistently updated.

Written by the indexing model from the issue text.