Fix scroll methods for e2e tests

[anastasiyaig]

Bug Report

Description

There are 2 scrolls now in framework:

• scroll for ScrollView:

  status-desktop/test/e2e/gui/elements/scroll.py

  Line 15 in 9050459

  def vertical_scroll_down(self, element: QObject, timeout_sec: int = 5):

• scroll for Flickable:

  status-desktop/test/e2e/gui/elements/scroll.py

  Line 33 in 9050459

  def old_vertical_scroll_to(self, element: QObject, timeout_sec: int = 5):

There are 2 problems here:

1. scroll for ScrollView is applicable only for ScrollView, so I can't use it for ListView for example
2. scroll for Flickable is buggy and leads to infinite scrolling. Some changes landed because of this assumption chore: reworked scroll method #15513 in this PR, so we basically moved to use scroll for scrollView. But the initial problem with Flickable scroll is the method implementation. To fix this issue I probably need to check if the view is at the end, because flick never scroll infinitely, always till the end (or till the beginning) of scroll view object
3. issue with both implementations. Both functions are receiving a qml object and want to scroll until this object is visible. But the delegates in listviews are lazy and are created only when the object is close to being visible.
   So it's only good to scroll to an object close to the view

Suggested implementation per @alexjba

// Some pseudocode

function object_in_view(flickable, object)
    return object.exists &&
           object.y > flickable.contentY - flickable.originY && // check if the object is below the current top of the view
           object.y + object.height < flickable.contentY - flickable.originY + flickable.height // check if the object is above the current bottom of the view

function scroll_to_object(flickable, object)
    flickable.contentY = flickable.originY //move at beginning

    if object_in_view
        return
    while !flickable.atYEnd
        flick
        if object_in_view
            return

Also, if we have an index and want to scroll to it in a ListView, we can easily use https://doc.qt.io/qt-5/qml-qtquick-listview.html#positionViewAtIndex-method. Same with GridView. That might be worth implementing as well

[anastasiyaig]

To properly fix that, i would need assistance from QML experts