Move zoom controls, show only one viewport

Adding https://www.drupal.org/project/experience_builder/issues/3481658 ✨ When zooming the canvas, update the scroll pos. to center on the mouse cursor Active as a related issue - would be nice to get the mouse cursor centering in along with this change!

This looks good and there are enough related followups happening to clean up any loose ends in MRs with a more manageable number of files changed.

Unpostponed #3515828-4: Zooming the canvas needs perf. improvements → .

While our heads are in this space, can we efficiently tackle (title-wise related) 🐛 Need to update the position of edit dropdown menu while zooming out/in in the canvas Active too?