Rework Notifications into NotificationContainer and Expose notifications API from Mantine

[BSd3v]

We need to rework the NotificationProvider and Notifications components into another NotificationContainer and expose the underlying notifications API from Mantine. This change will help us better manage notifications and provide more flexibility in how they are displayed and handled.

Tasks:

• Rework the NotificationProvider component into NotificationContainer. (notifications stream into the container and work with the queue to ensure all notifications are from callbacks are displayed before being removed)
  • expose props for api (clean, cleanQueue)
  • notifications handle for {add, update, hide}?
• Expose the underlying notifications API from Mantine. (dash_mantine_components.notification_container similar to dash_ag_grid.getApi)
• Update documentation to reflect these changes. (deprecate NotificationProvider and Notifications for v1 and remove in v2)

Additional Context:
The current Notifications component has limitations in terms of flexibility and customization. This is also not a good pattern for the notifications as Mantine itself only has the single component. The components are also stuck in the dash eco-system unless replaced or removed. (eg. Patch never removes) By exposing the notifications API from Mantine, we can leverage its full capabilities and provide a more robust solution for managing notifications.

[AnnMarieW]

Thanks for the write-up @BSd3v
For a little more background see #523 and #522