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:

### - n -

- name : SrcInfo , AgoraMediaPlayerSrcInfo , AgoraMusic
- network_transport_delay : RemoteAudioTrackStats
- networkTransportDelay : RemoteAudioStats , AgoraRtcRemoteAudioStats
- next() : IIterator
- None : IRtmpLocalUser
- NS_DELAY : ILocalUser
- NS_LEVEL : ILocalUser
- NS_MODE : ILocalUser
- NsNG : ILocalUser
- NsNGStatistical : ILocalUser
- ntpFracPerSecond : NtpTime
- NtpTime() : NtpTime
- ntpTimeMs : AudioPcmDataInfo
- nullopt_t() : nullopt_t
- num_channels : IScreenCaptureSource::AudioCaptureConfig , RemoteAudioTrackStats
- num_channels_ : AudioPcmFrame
- number_of_streams : LocalVideoTrackStats
- NumberOfCapabilities() : ICameraCapturer::IDeviceInfo
- numberOfChannels : EncodedAudioFrameInfo , RtmpStreamingAudioConfiguration
- NumberOfDevices() : ICameraCapturer::IDeviceInfo
- numChannels : LocalAudioStats , RemoteAudioStats , AgoraRtcLocalAudioStats , AgoraRtcRemoteAudioStats