Display notification to refresh page if socket disconnects

[reichert621]

Description

Display notification to refresh the dashboard if socket disconnects.

This is a temporary solution until we can figure out a good way to reconnect a disconnected socket.

Issue

https://github.com/papercups-io/papercups/issues/774

Screenshots

Checklist

• [x] Everything passes when running mix test
• [x] Ran mix format
• [x] No frontend compilation warnings