Agora RTC Objective-C API Reference Refactor

Here is a list of all struct and union fields with links to the structures/unions they belong to:

### - h -

- has_value() : Optional< T >
- hasAudio : UserInfo
- HasOneRef() : RefCountedObject< T > , RefCounter , RefCountInterface
- hasPath() : ISyncClient
- hasVideo : UserInfo
- hasVideoFilter() : IVideoTrack
- hdr10MetadataInfo : ExternalVideoFrame
- Hdr10MetadataInfo() : Hdr10MetadataInfo
- hdr10MetadataInfo : VideoFrame
- heartbeatInterval : AgoraRtmClientConfig
- height : ExternalVideoFrame , VideoFrame , MediaRecorderConfiguration , EncodedVideoFrameInfo , ExtensionEncodedImage , ExtensionVideoCodecSettings , ImagePayloadData , InjectStreamConfig , LiveTranscoding , LocalVideoTrackStats , MixerLayoutConfig , PublisherConfiguration , Rectangle , RemoteVideoStats , RemoteVideoTrackStats , RtcImage , RtmpStreamingVideoConfiguration , SimulcastStreamProfile , TranscodingUser , TranscodingVideoStream , VideoCompositingLayout::Region , VideoDimensions , VideoFormat , VideoFrameData , WatermarkBuffer , VideoLayout , AgoraEncodedVideoFrameInfo , AgoraExtVideoFrame , AgoraFacePositionInfo , AgoraMediaRecorderConfiguration , AgoraMetaSceneDisplayConfig , AgoraOutputVideoFrame , AgoraRtcRemoteVideoStats , AgoraVideoFilterFrame , AgoraVideoFrame , AgoraVideoLayout , AgoraVideoLayoutInfo , WatermarkBuffer
- highLightColor : ScreenCaptureParameters , AgoraScreenCaptureParameters
- highLighted : AgoraScreenCaptureParameters
- highLightWidth : ScreenCaptureParameters , AgoraScreenCaptureParameters
- HighQuality : ILocalUser
- hw_ear_monitor : ILocalAudioTrack::LocalAudioTrackStats
- hw_encoder_accelerating : LocalVideoTrackStats
- hwDecodingLevel : CodecCapLevels , AgoraVideoCodecCapLevels
- hwEncoderAccelerating : LocalVideoStats