fix(ai-message): message streaming animation

- Enhanced `AIMarkdownStreamingMessage` to use a stable reference for the `isStreaming` state, ensuring consistent rendering during updates.
- Updated `MarkdownAnimateText` to handle number inputs and preserve element structure for valid React elements, improving flexibility in rendering.
- Added logic in `TokenizedText` to skip rendering completely empty tokens and preserve whitespace-only tokens without additional DOM elements.

These changes aim to enhance the rendering logic and user experience in the AI chat interface by providing more robust handling of various input types and improving performance during streaming.

Signed-off-by: Innei <tukon479@gmail.com>

Author: Innei