relay warnings from ssdtools to user

[sebdalgarno]

this could use notification windows that appear at the bottom of the screen and disappear after a while.

Many times a user thinks there is a bug with the app. I think seeing the warning message would make it more clear that ssdtools is struggling behind the scenes with a specific argument value or dataset.

[sebdalgarno]

Kamino closed and cloned this issue to poissonconsulting/shinyssdtools