feat: Add an endpoint to list active app candidates

[mykola-mokhnach]

Such endpoint could be useful if there are multiple apps running at the same time and we need to figure out which of them to activate manually in order to perform various on-screen interactions.

[KazuCocoa]

This change itself is good, but this didn't show up com.apple.ContactsUI.LimitedAccessPromptView.

When an app is foreground, it shows:

{
    "value": [
        {
            "isActive": 1,
            "state": 4,
            "processArguments": {
                "env": {},
                "args": []
            },
            "pid": 1518,
            "bundleId": "com.google.calendar"
        }
    ],
    "sessionId": null
}

When the contact permissions view is in the front of the app:
(no com.apple.ContactsUI.LimitedAccessPromptView was in this endpoint result)

{
    "value": [
        {
            "isActive": 1,
            "state": 4,
            "processArguments": {
                "env": {},
                "args": []
            },
            "pid": 1251,
            "bundleId": "com.apple.springboard"
        }
    ],
    "sessionId": null
}

Home screen:

{
    "value": [
        {
            "isActive": 1,
            "state": 4,
            "processArguments": {
                "env": {},
                "args": []
            },
            "pid": 1251,
            "bundleId": "com.apple.springboard"
        }
    ],
    "sessionId": null
}

in session endpoint as well.

[mykola-mokhnach]

Thanks for checking it with iOS 18.
If the dialog is not listed then this endpoint won't be very useful :(
I'd prefer to close the PR for now