Add a possibility to override AccessibleObject methods like getPropertyValue and others in third-party code

### .NET version

8.0

### Did it work in .NET Framework?

No

### Did it work in any of the earlier releases of .NET Core or .NET 5+?

_No response_

### Issue description

Hello.

We need to override getPropertyValue of a form at this moment to implement UIA_is_dialog_property_id in the form without showing it as a dialog, because an app, by design shouldn't be blocked, but we also need screenreader to read a label on focus as it is done when form is beeing showed as a dialog.

Is there any other possiibility to do that at this moment?

Please consider making AccessibleObject methods public to make it possible for third-party developers to have more customizations in their apps.

### Steps to reproduce

Try to focus a form with label, progress bar and a cancel button with a screenreader
In our case label with information should be read