Feature request: Portal sidebar customizations: Ability to group/nest/collapse sidebar links, and ability to add arbitrary bookmarks to the sidebar

[daiplusplus]

This is my current Azure Portal sidebar - so-far all I (or anyone) can do is add top-level Portal blades for a single resource-type:

As yu can see, we can't really do much with it, which is disappointing; so I'd like to customize it so it's more useful for my exact and personal needs:

• I'd like to make the sidebar items more compact (smaller font-size, less padding/margin; shorten the text: "Microsoft Defender for Cloud" could be "Cloud Defender" and fit on a single line, etc).
• I'd like to organize them into groups (with group-headings) and collapse/expand groups as needed (but I don't need or want a full tree-view, that would be too fiddly)
• It'd be nice if there was a (Windows 7/8/10) Jump-List style menu for each link that that shows the top 20 most-recently-interacted-with resources under that blade.
• I'd also like to be able to add my own links/bookmarks to the sidebar (either as a top-level item or within the groups I described above): these could be links to places within the Azure Portal - or arbitrary hyperlinks.

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This is something I'm happy to implement and submit as a PR.