Panel resizing can get into strange states

[johtso]

Sometimes when resizing the panel it will get into a state where it thinks that the mouse is pressed when it isn't, and vice versa.

Also very minor, but while dragging to resize the panel sometimes all text on the page gets rapidly selected and deselected. Not entirely sure when that happens.

[johtso]

I guess an issue with how drag session tracker detects the end of the drag session https://github.com/statelyai/xstate-viz/blob/dev/src/dragSessionTracker.ts