[Lens] Add additional drag and drop states including "partially allowed" state

[wylieconlon]

Follow up to #75895

From @cchaos :

Since we're getting really reliant on indicating state and interaction through the visuals of the drag and drop elements, I've come up with a style guide.

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[cchaos]

I'm going to expand this particular issue to include updating the visual states for all interactions as well and I'll update the summary.

[wylieconlon]

@cchaos the style guide is looking very close, but I am not sure that we will be able to style the currently-dragged item. The main reason is that the drag cursor is converted to an image when the drag begins. There may be a workaround to this that I'm not aware of, but this is why we don't have special styles for the currently-dragged item right now.

[flash1293]

As decided offline: Moving this out of 7.10 for now to focus on #54589 as it has a bigger user impact and we might not get to both

[cchaos]

This is something I can try to take on for 7.10

[flash1293]

Cool, thanks a lot for your help, @cchaos !