Update some example notebooks

replaceOutput runs without flickering the GUI

Update some example notebooks to the latest notebook version, so that
when they start, Jupyter doesn't immediately update them and mark them
as changed.

Also replace the fake diagrams test notebook with a real diagrams test
notebook. The fake diagrams test notebook was actually the charts test
notebook.

Also export `OutputMsg` constructors so that users can call
`setField` on an `OutputWidget` to write their own `replaceOutput`
functions.

Updated sample widget Notebooks

Updating IHaskell-widgets

This reverts commit e3a5ae79.