Agora RTC Objective-C API Reference Refactor

### - w -

- watermark : LiveTranscoding
- watermarkCount : LiveTranscoding
- watermarkRatio : WatermarkOptions
- width : VideoFrame , EncodedVideoFrameInfo , ImagePayloadData , InjectStreamConfig , LiveTranscoding , LocalVideoTrackStats , MixerLayoutConfig , PublisherConfiguration , Rectangle , RemoteVideoStats , RemoteVideoTrackStats , RtcImage , RtmpStreamingVideoConfiguration , TranscodingUser , TranscodingVideoStream , VideoCompositingLayout::Region , VideoDimensions , VideoFormat , VideoFrameData
- widthRatio : WatermarkRatio
- windowFocus : ScreenCaptureParameters
- windowId : ScreenCaptureConfiguration