Update circuits widget sizing behavior

[swernli]

This change fixes a few quirks of the Circuit widget, specifically:

• if the width of the widget is greater than the width of the cell output area, scroll bars are added, and
• setting a custom zoom level by changing the value in the zoom control disables the resize handling so that VS Code doesn't incorrectly trigger a recalculation of the default zoom and undo the manual change.

Confirmed with manual testing that window resizing in VS Code circuit display is still hadled properly.

[minestarks]

@swernli thanks for digging into this. I pushed my fix over your fix :D I think it works, but I would appreciate if you tested it in the environment where you saw the bug.

[swernli]

@swernli thanks for digging into this. I pushed my fix over your fix :D I think it works, but I would appreciate if you tested it in the environment where you saw the bug.

The resizing and zoom work great where I tested them, but it looks like the scrolling fix got lost in the shuffle. I pushed that up, and now I think we are good to go.

@billti I think this may fix the issues you were seeing in Python interactive as well.

[minestarks]

@swernli oops, sorry, yes, thanks for fixing that! Teamwork! ✊