feat: video publishing (#42)

- Prepare webrtc abstraction ( for future wasm support )
- Added track publish support for videos
  - Added LogoTrack example to simple_room demo
- Lot of cleanup
- There are compiler warnings I'll solve on our v1 release

webrtc-sys/src/video_frame.rs

@@ -21,7 +21,6 @@ pub mod ffi {
         include!("livekit/video_frame.h");
 
         type VideoFrame;
-        type VideoFrameBuilder;
 
         fn width(self: &VideoFrame) -> i32;
         fn height(self: &VideoFrame) -> i32;
@@ -32,18 +31,18 @@ pub mod ffi {
         fn transport_frame_id(self: &VideoFrame) -> u32;
         fn timestamp(self: &VideoFrame) -> u32;
         fn rotation(self: &VideoFrame) -> VideoRotation;
-        fn video_frame_buffer(self: &VideoFrame) -> UniquePtr<VideoFrameBuffer>;
+        unsafe fn video_frame_buffer(self: &VideoFrame) -> UniquePtr<VideoFrameBuffer>;
 
-        fn set_video_frame_buffer(
-            self: Pin<&mut VideoFrameBuilder>,
-            buffer: UniquePtr<VideoFrameBuffer>,
-        );
+        // VideoFrameBuilder
+        type VideoFrameBuilder;
+        fn new_video_frame_builder() -> UniquePtr<VideoFrameBuilder>;
         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 set_video_frame_buffer(self: Pin<&mut VideoFrameBuilder>, buffer: &VideoFrameBuffer);
+
         fn build(self: Pin<&mut VideoFrameBuilder>) -> UniquePtr<VideoFrame>;
 
-        fn create_video_frame_builder() -> UniquePtr<VideoFrameBuilder>;
     }
 }