- use `OpenAI` and `Azure.AI.OpenAI`
- use `developer` role instead of `system` for OpenAI's `o1` series models
- use streaming response
- re-design `AIAssistant`
Signed-off-by: leo <longshuang@msn.cn>
* use system chrome instead of custom caption button on macOS
* move `BeginMoveWindow` and `MaximizeOrRestoreWindow` to `ChromelessWindow`
* better supports for fullscreen mode on macOS
* redesign the layout of title bar for all windows
Signed-off-by: leo <longshuang@msn.cn>