Fix react18 concurrent mode drag glitch due to state inconsistency

[erictheswift]

fixes #698

[maxwellwalin]

Confirmed that it solved the same issue I was having when I upgraded to React 18.

[DeepAnchor]

This fixed an issue I was having when dragging an item very quickly across the screen.

As in #698, the dragged item would move progressively further and further away from the cursor proportionate to the dragging acceleration (which makes sense since this issue is caused by React 18 batching).

Thanks @erictheswift for investigating and fixing this!

LGTM

[tnrich]

@STRML can we please get this on in? Thank you!

[STRML]

Assigning directly to state is a pretty bad habit.

That said, you are correct that this data is not used for rendering, so it shouldn't be on this.state at all! Instead, it should simply held as local variables on the component.

If you make that change, I'll merge it.

[erictheswift]

Agree)
My initial intent was to make patch be as minimum surface area as possible

[erictheswift]

@STRML done

[STRML]

Thanks!