Provide an emulator for local development and integration tests #843
Description
Is your feature request related to a problem? Please describe.
It's now not possible to develop or run integration tests locally without an internet connection.
Describe the solution you'd like
An emulator (similar to what's available for SignalR) should make local development and integration tests easier and less cumbersome. Additionally it could also be included in the Aspire .NET Azure Web PubSub integration.