Flag for preventing outside click behaviour

[agcty]

The Dialog component is great but we're running into a lot of headaches when it comes to outside click behavior as described in #621. Especially working with toasts is a real pain at the moment and a lot of people have also seem to have similar issues.

Proposal:

Add a flag that lets you disable closing the dialog on outside click

#768 could also work but an explicit flag might make it more developer-friendly

[soulsam480]

This will be superr helpful