ComboBox Accessibility Issues on Various Platforms

ComboBox has significant Accessibility issues on Windows, macOS, Android and iOS.

1. Windows: After opening the ComboBox popup and using arrow keys to change item selection, the Narrator screen reader does not read items within the popup.
   Note: Narrator successfully reads the selected item after closing the popup. Also, it reads the selected item when arrow keys are used to change selection without opening the popup.
2. macOS: After opening the ComboBox popup and using arrow keys to change item selection, the VoiceOver screen reader fails to read items within the popup.
3. Android: The TalkBack screen reader fails to focus on the ComboBox when swiping right to navigate through controls on a screen. This prevents users from interacting with the ComboBox.
4. iOS: Turn on the VoiceOver screen reader, open the ComboBox popup and swipe-right to attempt to select an item in the popup. Focus moves to the next control (specifically, the RadioButton in the sample below) and the user is unable to select items within the popup.

To repro, use the ComboBox code in https://doc.qt.io/qt-6/qtquickcontrols-customize.html#customizing-combobox Then add a control after the ComboBox.

For example,

ComboBox {
  // Copy ComboBox code from https://doc.qt.io/qt-6/qtquickcontrols-customize.html#customizing-combobox
}

RadioButton {
   text: qsTr("Test")
}