In the newly released (6.1.2 at the time of writing) leafygreen toast version, the interface has been updated and the styles are better. Support for a toast stack was also added. Updating will improve the toast experience in Compass. Down the line we could also enable multiple import/export operations to run in parallel, but that's separate from this ticket. There's also a hook interface we can use, as well as push/pop/update although we might not need those as we do that already in use-toast (to be investigated in this ticket, might be better to use them as they are how they're planning to be supported in future).

This ticket involves updating our `@leafygreen-ui/toast` dependency in compass-components to a version > 6.
Note: There are some styling overrides marked with TODO(COMPASS-6808) we can remove after updating.

https://github.com/mongodb/leafygreen-ui/blob/main/packages/toast/CHANGELOG.md 

https://www.mongodb.design/component/toast/example/