Change the data panels for exported picture

[tonysherbondy]

Should be able to use a popupUI to examine and alter the input data to a picture.

[tonysherbondy]

Use the popup from #9 and then have the data from pictures in the popup. This will also require #11 and #12.

[tonysherbondy]

• DrawPictureInstruction will create DataVariables for each DataVariable inside the picture. And then rewrite any expression of each of those variables so that they can only depend on the new DataVariables.
• Stroke, StrokeWidth, Color, become variables on a DrawInstruction as well
• Rewrite Popup to treat props as DataVariables
• Evaluate the shape variables directly rather than accessing shapes
• DrawPicture DataVariables hopefully don't need any special treatment
• These DataVariables are not persisted, they are simply a map inside of the DrawPictureInstruction
• Somewhere in App (similar to getAllDataVariables), we will ask the DrawPictureInstruction for its list of variables and then compute the value for them.
• The value will be stored in a map with key of the DrawPictureInstruction id.
• Inside of utils.picture, we will change a utils.dataIDMap, that getData will use to dereference the ID that it is looking for for the one in variables.pictureData[pictureId].id