fix: display error messages during installation

[imobachgs]

Problem

If something goes wrong during packages installation, Agama web UI does not show any message. We
found out that there are some problems:

• When the connection goes down, TanStack Query will not perform any request (until the network is
  up).
• The UI might loose the QuestionsChanged event if it is reconnecting the WebSocket at that point.

Solution

To overcome those problems, we have introduced the following changes:

• Set TanStack Query network mode to "always" when running on localhost.
• Invalidate questions query when the WebSocket is reconnected to make sure we do not miss any
  message.

Note

We could play with the refetchOnReconnect setting at global level. But let's be conservative at
this point.

Additional changes

agama-web-server:

• Exit the WebSocket handler when the client is disconnected
• Log the events

web UI:

• refactor(web): expose onerror and onclose at WSClient level

Testing

• Tested manually

Screenshots