[Feature Request] Expose raw video frames (CVPixelBuffer/MTLTexture) for custom post-processing and MetalFX Upscaling

Could you please add a way for the app to access raw video frames during playback in the IVS Player SDK? Right now, the player is very restrictive in that doesn't let us touch the video data before it hits the screen. This makes it impossible to use modern features like Apple’s MetalFX to upscale 1080p streams to 4K in real-time.

Instead, adding a simple frame-output callback would allow us to make 1080p streams look significantly sharper on high-resolution displays without needing more bandwidth. Standard players like Apple's AVPlayer already allow this, and adding it to IVS would make it possible to provide a better experience for developers and users alike.

Start by reviewing how the sample apps integrate the Amazon IVS Player iOS SDK and whether the SDK exposes any frame-output entry point. The request is complete when developers can receive raw video frames as CVPixelBuffer or MTLTexture during playback for custom processing such as MetalFX upscaling.

Written by the indexing model from the issue text.