[GUI][ControlGroupList] Update scroller sizes when list size changes

[enen92]

Description

This fixes the scroller size and position for cases in which the respective container is updated to contain additional items. This is visible for example in the addon settings dialog when you enable a setting that changes the visibility status of other items in the same list.

@CastagnaIT I think you'll have to be the testing monkey here :)

Motivation and Context

Fixes #18637

How Has This Been Tested?

With netflix settings dialog as shown in the issue report. Tested a bunch of other windows with no regressions observed.

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

[ronie]

@enen92 it's not working as expected for me...
in my test i used these addon settings: https://paste.kodi.tv/raxawidogi

addon settings dialog:

expected result after enabling the first setting:

actual result after enabling the first setting: the list scrolls to the end

[enen92]

Good catch @ronie, thanks

[CastagnaIT]

@enen92 I can confirm the same behavior with the old setting version

[enen92]

@ronie @CastagnaIT please retest

[ronie]

perfect! :-)