Agora RTC Objective-C API Reference Refactor

### - c -

- cacheSize : AgoraMediaPlayerCacheStatistics
- cacheStatistics : AgoraMediaPlayerUpdatedInfo
- captureAudio : AgoraScreenCaptureParameters2
- captureMouseCursor : AgoraScreenCaptureParameters
- captureSignalVolume : AgoraScreenAudioParameters
- captureTimeMs : AgoraEncodedVideoFrameInfo
- captureTimestamp : AgoraAudioPcmFrame
- captureVideo : AgoraScreenCaptureParameters2
- ccMode : AgoraEncodedVideoTrackOptions
- channelId : AgoraEchoTestConfiguration , AgoraExtensionInfo , AgoraRecorderStreamInfo , AgoraRtcConnection
- channelName : AgoraChannelMediaRelayInfo , AgoraRtmMessageEvent , AgoraRtmPresenceEvent
- channelNumbers : AgoraAudioPcmFrame
- channelProfile : AgoraRtcChannelMediaOptions , AgoraRtcEngineConfig
- channels : AgoraAudioFrame , AgoraEncodedAudioFrameInfo
- channelTopic : AgoraRtmMessageEvent
- channelType : AgoraRtmMessageEvent , AgoraRtmPresenceEvent
- chartName : AgoraMusicChartInfo
- clientRoleType : AgoraRtcChannelMediaOptions
- climaxSegmentList : AgoraMusic
- codecCapLevels : AgoraVideoCodecCapInfo
- codecCapMask : AgoraVideoCodecCapInfo
- codecName : AgoraRtcMediaStreamInfo
- codecType : AgoraEncodedAudioFrameInfo , AgoraEncodedVideoFrameInfo , AgoraEncodedVideoTrackOptions , AgoraVideoCodecCapInfo
- color : AgoraVirtualBackgroundSource
- compressionPreference : AgoraAdvancedVideoOptions
- connectTimeMs : AgoraChannelStats
- containerFormat : AgoraMediaRecorderConfiguration
- contentHint : AgoraScreenVideoParameters
- count : AgoraMusicCollection
- cpuAppUsage : AgoraChannelStats
- cpuTotalUsage : AgoraChannelStats
- cropArea : AgoraRtcVideoCanvas
- cropBottom : AgoraVideoFrame
- cropLeft : AgoraVideoFrame
- cropRight : AgoraVideoFrame
- cropTop : AgoraVideoFrame
- customVideoTrackId : AgoraDirectCdnStreamingMediaOptions , AgoraRtcChannelMediaOptions