Expose additional mouse::Interaction cursors

[airstrike]

This PR adds a few more common mouse interaction cursors to interaction.rs, namely:

• Resizing diagonally in both directions (pick the right name is probably the hardest part here)
• Zooming out (we already had a cursor for zooming in but not one for zooming out)
• Cell selector (used in Microsoft Excel and possibly other spreadsheet or table-like UI elements)
• Move

Since the Cell selector is a bit niche, here is a screenshot of what it looks like in Excel. My use case is building a spreadsheet app, so users would expect this cursor to be there.

I take it ZoomOut and Move are pretty standard and need no specific use case.

There's an argument to be made that iced could just expose all of the cursors from winit and let the users figure it out, even if some of the cursors are very unusual. I'm not making that argument so I have only added those cursors whose inclusion was more immediately defensible IMHO but open to suggestions.

Admittedly I have not tested the specific resizing cursors because I'm on MacOS and they don't work, but naturally everything compiles and runs fine. They just default to the standard cursor, but I tested other cursors from winit and they were fine (including, for example, sizing westward, which is not in this PR) so I'm confident nothing's wrong with the code per se.

FYI this winit issue is being tracked here: rust-windowing/winit#3724

[airstrike]

Also maybe we have to wait until the winit issue is fixed before merging buggy cursors into iced, but I didn't want to forget about this PR so I'm submitting it now as it's unlikely the code will break between now and when it gets merged and we can at least track it, debate names and debate including additional cursors.

[stevenxxiu]

I also would love to add another cursor, being the copy cursor.

I'm porting a Conky like project of mine, from GTK to Iced. Iced feels like a more direct toolkit than using the GTK Rust wrapper.

The use case is when I hover my cursor over some labels, I show a copy cursor to indicate the text can be copied.

Since this is a dashboard, the UI should be kept very simple. So I felt like a cursor was the best way to go.

[hecrj]

Thanks!

@stevenxxiu I added Copy as well.