Make left column responsive to width in all blockly puzzles.

Shrink left column in 50px increments from 400px to 200px on small displays. Shrink game visualization area accordingly, and redo layout for button and instruction areas.

screenshots: https://docs.google.com/a/code.org/document/d/1PMdB3eyVTlHuo-7k5gZN2_2Mw3isEUwuQ5sMc_UQbSg/edit#heading=h.drx8yzus8gc0