Move Rerun Code Above to a Modal

[aarondr77]

More than not, I see users ignore the rerun code above taskpane and try to use the Mito Spreadsheet, getting confused when it doesn't work.

This is exactly what a modal is great for. It is designed to force you to deal with it before doing anything else in the tool.

We should:

1. move it to a modal
2. improve the language to be more specific about what they need to do?