Touch up and merge of the toast component

[thiagomajesk]

We are waiting on: phoenixframework/phoenix_live_view#2563.

If there's a native way of doing this using LiveView we'll double down on using hooks for the library which will provide better integration with Phoenix by default. If not, we'll have to look at adding AlpineJs as a dependency (unfortunately).

Due to the impact on the API, development on this front is paused until we have more information on how to proceed.