* 1. Adds hardware_frames_constraints to retrieve valid HWPixelFormats and SWPixelFormats for specific hardware frame configurations.
2. Implements a HardwareFramesConstraints method in hardware_device_context to obtain these constraints for a given hardware frames context.
* Add AVPixFmtDescriptor to retrieve flags for AVPixelFormat
feat(PixelFormat): Expose `AVPixFmtDescriptor` via `Descriptor()` method
This commit introduces support for `AVPixFmtDescriptor`, which provides
detailed information about an `AVPixelFormat`, including its flags.
A new `Descriptor()` method has been added to the `PixelFormat` type
(or class) to retrieve its corresponding `AVPixFmtDescriptor`. This allows
for easier access to extended properties of pixel formats.
