Linking pages improvements (meta issue)

This meta issue is here to track possible link handling improvements

• Linking a page should be the first and most obvious way of linking in Collectives. One solution would be a new toplevel entry "Link to page" in the link section of the Text menubar. This entry could open the "Collectives pages" picker in the smart picker. #2332
• The "Collectives pages" picker in the smart picker could provide a page picker (similar to the move/copy modal) additionally to just listing search results. #2470
• When adding a link via smart picker, we should add a markdown link with the page title as title (like [page title](/link/to/page.md?fileId=123)) instead of just pasting the URL. #949
• When clicking a link in edit mode, it should open a popover that allows navigating to the link and/or editing the link. #845
• Link previews could show only on hover/click instead of being displayed all the time. We got quite a few complaints about link previews cluttering the page. Also related to #845
• https://github.com/nextcloud/collectives/issues/1573
• https://github.com/nextcloud/collectives/issues/1882
• https://github.com/nextcloud/collectives/issues/1073
• https://github.com/nextcloud/collectives/issues/1583
• https://github.com/nextcloud/collectives/issues/1584