fix: Address 4 Accessibility Bugs

[haoliuu]

Fixed following 4 Accessibility Bugs:

1. [AI Dev Gallery] [Samples] [Image->Detect Objects]: Keyboard focus is not visible anywhere on the screen after closing "Open" dialog box.
2. [AI Dev Gallery] [Samples] [Text->Generate Text]: "Browse and download generative models from Hugging face" text got truncated after applying text scaling.
3. [AI Dev Gallery] [Samples] [Image-Detect Human Pose]: Keyboard focus is not visible on "Select Image" button.
4. [AI Dev Gallery] [Samples] [Image->Detect Human Pose]: The Name property must not include the element's control type.

[Copilot]

Pull request overview

This PR claims to fix 4 accessibility bugs but only implements one fix. The change adds text wrapping and center alignment to prevent text truncation when text scaling is applied in the Hugging Face model search interface.

Changes:

• Added TextWrapping="Wrap" and TextAlignment="Center" to the descriptive text in the model search UI to prevent truncation with text scaling