Explicitly hide inactive view pages
Use XInitThreads() on X11 to enable loading the visualizer module
Add icon() method to ViewPage api and use that and title() for sidebar items
Clean up
Revert "Add icon() method to ViewPage api and use that and title() for sidebar items"

We can't lazy load the page when we need its members to show the sidebar
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This reverts commit 1821b24391c33b2ea14fc0d094142395588075d9.
Allow to set icon and text for externally added generic page items without instantiating them (aka fix lazy loading for vsxu widget)