[V3 Todo] New default "auto" relative layout engine (with auto popup/tooltip alignment)

[adamscybot]

The decision between fit-parent and fit-content is irritating and unclear. If the user wants to tweak the icon position sufficiently, and/or have tooltip/popups as well, you can't easily get it right with certain anchoring without falling back to fit-parent.

fit-parent is not ideal because it means you must define the icon size. We would rather defer that to the component itself.

A new auto layout engine is to be added as a clear default that covers all of these use cases. It should:

• Always defer size of the icon to the component itself (like fit-content). No expensive recalcs if the size changes. Just works dynamically.
• The user should be able to define common icon anchor positions like top, bottom-right etc etc, as well as provide a custom value as a % value relative to the icons own size.
• The user should be able to use tooltips/popups and they just work with positioning similar to the default but automatically scaling to the size of the icon.
• All positions to support tweaking by pixel values relative to the anchor point.