Agora RTC Objective-C API Reference Refactor

### - i -

- ImagePayloadData() : ImagePayloadData
- ImageTrackOptions() : ImageTrackOptions
- IncRef() : RefCounter
- Increment() : AtomicOps
- Init() : OptionalStorageBase< T >
- initialize() : AParameter , IAgoraService , IRtcEngine , IRtmService
- initializeCapture() : IScreenCaptureSource
- initializeVQA() : IAgoraVideoQualityAnalyzer
- InitOrAssign() : OptionalBase< T >
- initRecording() : IRecordingDeviceSource
- initVideo() : IScreenCaptureSource
- initWithChannelId:localUid: : AgoraRtcConnection
- initWithConfig:delegate: : AgoraRtmClientKit
- initWithLiveKit: : AgoraLivePublisher , AgoraLiveSubscriber
- initWithToken: : AgoraChannelMediaRelayInfo
- initWithWindowId() : IScreenCapturer
- InjectStreamConfig() : InjectStreamConfig
- isAudioValid() : IMediaStreamingSource
- isEnabled : <AgoraAudioFilterDelegate> , <AgoraVideoFilterDelegate> , IAudioFilter , ILocalAudioTrack , IVideoFilter
- isExtensionFilter() : IExtensionVideoFilter , IVideoFilter
- isExternal() : IVideoFrameObserver , IVideoFilter
- isExternalSink() : IVideoSinkBase
- isFeatureAvailableOnDevice() : IRtcEngine
- isFeatureAvailableOnDevice: : AgoraRtcEngineKit
- isPreloadedWithSongCode: : AgoraMusicContentCenter
- isSceneDownloaded: : AgoraMetachatKit
- isSecure : AgoraRtcEngineKit
- isSupportPortraitCenterStage : AgoraRtcEngineKit
- isVideoValid() : IMediaStreamingSource