[Feature] Add streaming ability in chat page using Azure SignalR service

[phanthaiduong22]

Purpose

• Currently, on the Chat page, when we ask a question, the system gathers all information (e.g., answer, thought, supportingContent, etc.) and responds to the client through the API.
• We are adding streaming capability. Whenever the LLM responds with an answer in a streaming format, we can use a SignalR connection (WebSocket) to push messages directly.

Does this introduce a breaking change?

[x] Yes
[ ] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[X] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]

• Test the code

azd up

• Go to the Chat page.
• There will be options to select between streaming mode and normal mode.

What to Check

Verify that the following are valid

• Verify normal mode is working as previously
• Verify streaming mode is working as expected

Next steps:

• Add unit tests
• Add docs
• Verify running locally without AzureSignalREndpoint env configure

Other Information

[jmatthiesen]

Thank you for the PR! This looks like a good approach to use for performance optimization and I think we should provide it as an option to customers. At the same time, we're working to have the main branch demonstrate the patterns used by AI libraries by default, such as Streaming APIs that they provide. @LittleLittleCloud suggested a great idea in an internal discussion - create a separate branch for this work and mention it in the Readme for the main branch. This is what we do for Redis support as well and it's a good way to present alternate architectures without increasing complexity on the default sample.