Images/sounds not working correctly due to changing from kasandbox to kastatic urls

A lot of programs aren't working anymore because for some reason, KA is using kastatic.org URLs instead of kasandbox.org.

For example, a sound URL KA used to use: https://www.kasandbox.org/programming-sounds/rpg/metal-clink.mp3
What it uses now (this link is broken): https://cdn.kastatic.org/third_party/javascript-khansrc/live-editor/sounds/rpg/metal-clink.mp3

Or image URL: https://www.kasandbox.org/programming-images/animals/fox.png to https://cdn.kastatic.org/third_party/javascript-khansrc/live-editor/build/images/animals/fox.png

So that's one thing, the new sound URLs don't even work.

But for images, the image URLs work, and `image()`/`getImage()` seem to work, but then when you try to call `get()` after displaying an image, it errors.

Start by reproducing the broken kasandbox.org and kastatic.org sound and image URLs, then test the reported sequence using image(), getImage(), and get(). Done means sound URLs load correctly and calling get() after displaying an image no longer errors.

Written by the indexing model from the issue text.