Improve loading state feedback for LLM responses

[jdisho]

Problem

When you’re waiting for a response from the LLM, you’ll see a spinner in the top-left corner of the chat interface. IMO this has a couple of drawbacks:

• The placement of the spinner isn’t very intuitive, making it easy to overlook.
• It also blocks you from closing the chat view while the response is still loading.

Solution

• Instead of a spinner, we could use an ellipsis (”…”) that animates right where the response will appear, making it clear where to look for the incoming message.
• We should also allow users to close the chat window during this time. Any pending requests should be canceled and cleaned.

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct and Contributing Guidelines

[PSchmiedmayer]

Great idea; we should look at the functionality in SpeziChat, we already support some message typing indicator that we could use here.