Toggle console auto-scroll

[Hal-9k1]

As of #28, the AppConsole auto-scrolls with each new received message. While sometimes convenient, this makes it hard for old output to be read if we are still receiving messages from the robot. A toggle button for this behavior on the editor toolbar would be nice. Also if possible this behavior should also be temporarily disabled when the user scrolls up in the AppConsole, and re-enabled when scrolling to the bottom.

Related files: Editor.tsx (to add an editor toolbar button), AppConsole.tsx