Add post-import info/confirmation modal

[bodom0015]

After importing a Tale, the user is given no indication of what to do next.

Furthermore, it is sometimes not clear that an import operation has actually occurred at all. In extreme cases, if the Tale imports quickly, there is little to no delay when redirecting to the Run view of the newly-created Tale.

We should add some sort of confirmation modal that says something similar to the following:

We have successfully imported a copy of this Tale for your use.
You are free to execute and/or modify the contents of the Tale as you see fit.

Click the Run button at the top-right to launch and Interact with the Tale.