[css-ui] Proposal: new cursor value all-resize

[jchv]

https://www.w3.org/TR/css-ui-3/#propdef-cursor

I am proposing the addition of a new cursor value all-resize.

The CSS cursor spec does a good job enumerating a common set of cursors that cover the needs of most software with reasonable names. As such, the CSS cursor names have been mostly adopted in the free software desktop world, e.g. in GTK's own cursor names, and in the recent Wayland cursor-shape-v1.

However, it appears that there is no specific cursor that covers the use case of a cursor that is for generally moving or resizing in all directions at once. This often looks like a combination of ns-resize and ew-resize:

This cursor is often used by image editing software to represent translation of a compositing layer. This is distinct from all-scroll, traditionally called fleur in Xcursor themes as far as I can tell, which usually looks something like this:

On some platforms, e.g. Apple computers, there appears to be no distinction, and the all-scroll cursor and all-resize cursor would likely map to the same system cursor. This doesn't seem to be a problem, because there are already cases where browsers map multiple cursor values to the same OS cursor.

I apologize if I have filed this issue incorrectly, please let me know and I'll do my best to make it correct. Thanks for your consideration.

[jchv]

This is probably a duplicate of #10115.