feat(Snackbar): Add an option to control whether opening a new snackbar prematurely closes existing ones

[ManelBH]

Feature Description

I propose having an option to control whether new snackbars automatically dismiss the existing one. When this autodismissal is disabled snackbars would be queued and shown for the specified duration one after another.

The current implementation is not fully compliant with the material specification which says:

Snackbars appear without warning, and don't require user interaction. They automatically disappear from the screen after a minimum of four seconds, and a maximum of ten seconds.
When multiple snackbar updates are necessary, they should appear one at a time.

Use case

Being able to have a material compliant option while keeping the original behaviour.