Box/lasso selection should be compatible with PTZ

[Keavon]

Box selection with the Select tool and Path tool doesn't follow the canvas when panning (via the mouse vertical/horizontal scroll wheel) or zooming (with Ctrl + or Ctrl -). The starting point of the rectangle should be locked down to the canvas location, not follow the viewport. This works correctly with the auto-panning feature (dragging the box selection off the edges of the viewport), so that code can be referenced. The actual box selection must still be rounded to viewport coordinates so the box selection is drawn cleanly (without fuzzy antialiasing). The video below shows the incorrect present behavior.

capture_8_.mp4

Discussion in this Discord thread: https://discord.com/channels/731730685944922173/1321358747133677599