* all panel icons are 16x16 in size; allow ToolbarButton to have its icon size set from outside;
* use TitleItem for streaming too, so that the style of focus-visible is the same
* allow menu icon to be visible when panel is focused
* remove some styling of title icons in panel header
* panel alert notices are too big
* PanelHeaderNotice: Fix styling issue with background and hover when
feature toggle is not enable
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Co-authored-by: Alexandra Vargas <alexa1866@gmail.com>
