Agora RTC Objective-C API Reference Refactor

Here is a list of all namespace members with links to the namespace documentation for each member:

### - o -

- OP_Privilege : agora::base
- OP_READ : agora::base
- OP_WRITE : agora::base
- operator!=() : agora::base , agora
- operator<() : agora
- operator<=() : agora
- operator==() : agora::base , agora
- operator>() : agora
- operator>=() : agora
- ORIENTATION_MODE : agora::rtc
- ORIENTATION_MODE_ADAPTIVE : agora::rtc
- ORIENTATION_MODE_FIXED_LANDSCAPE : agora::rtc
- ORIENTATION_MODE_FIXED_PORTRAIT : agora::rtc