RtpTransceiver bindings & requirements for publishing tracks (#39)

- RtpSender
- RtpReceiver
- RtpTransceiver
- RtpParameters
- VideoFrameBuilder
- Interior mutability on c++ side
- Cleanup bindings ( Use #pragma once instead of include guards )
     - webrtc-sys/src/* headers are now used in only one place 
     - Avoid confusion between generated headers and our headers
- AdaptedVideoTrackSource
- Cleanup the workaround with unsupported Vec<Shared<T>>
    - Put everything inside one file

webrtc-sys/src/video_frame.rs

@@ -11,12 +11,17 @@ pub mod ffi {
         VideoRotation270 = 270,
     }
 
-    unsafe extern "C++" {
-        include!("livekit/video_frame.h");
+    extern "C++" {
         include!("livekit/video_frame_buffer.h");
 
-        type VideoFrame;
         type VideoFrameBuffer = crate::video_frame_buffer::ffi::VideoFrameBuffer;
+    }
+
+    unsafe extern "C++" {
+        include!("livekit/video_frame.h");
+
+        type VideoFrame;
+        type VideoFrameBuilder;
 
         fn width(self: &VideoFrame) -> i32;
         fn height(self: &VideoFrame) -> i32;
@@ -29,7 +34,16 @@ pub mod ffi {
         fn rotation(self: &VideoFrame) -> VideoRotation;
         fn video_frame_buffer(self: &VideoFrame) -> UniquePtr<VideoFrameBuffer>;
 
-        fn _unique_video_frame() -> UniquePtr<VideoFrame>; // Ignore
+        fn set_video_frame_buffer(
+            self: Pin<&mut VideoFrameBuilder>,
+            buffer: UniquePtr<VideoFrameBuffer>,
+        );
+        fn set_timestamp_us(self: Pin<&mut VideoFrameBuilder>, timestamp_us: i64);
+        fn set_rotation(self: Pin<&mut VideoFrameBuilder>, rotation: VideoRotation);
+        fn set_id(self: Pin<&mut VideoFrameBuilder>, id: u16);
+        fn build(self: Pin<&mut VideoFrameBuilder>) -> UniquePtr<VideoFrame>;
+
+        fn create_video_frame_builder() -> UniquePtr<VideoFrameBuilder>;
     }
 }