Use livekit's Rust SDK instead of their swift SDK (#13343)

See https://github.com/livekit/rust-sdks/pull/355

Todo:

* [x] make `call` / `live_kit_client` crates use the livekit rust sdk
* [x] create a fake version of livekit rust API for integration tests
* [x] capture local audio
* [x] play remote audio
* [x] capture local video tracks
* [x] play remote video tracks
* [x] tests passing
* bugs
* [x] deafening does not work
(https://github.com/livekit/rust-sdks/issues/359)
* [x] mute and speaking status are not replicated properly:
(https://github.com/livekit/rust-sdks/issues/358)
* [x] **linux** - crash due to symbol conflict between WebRTC's
BoringSSL and libcurl's openssl
(https://github.com/livekit/rust-sdks/issues/89)
* [x] **linux** - libwebrtc-sys adds undesired dependencies on `libGL`
and `libXext`
* [x] **windows** - linker error, maybe related to the C++ stdlib
(https://github.com/livekit/rust-sdks/issues/364)
        ```
libwebrtc_sys-54978c6ad5066a35.rlib(video_frame.obj) : error LNK2038:
mismatch detected for 'RuntimeLibrary': value 'MT_StaticRelease' doesn't
match value 'MD_DynamicRelease' in
libtree_sitter_yaml-df6b0adf8f009e8f.rlib(2e40c9e35e9506f4-scanner.o)
        ```
    * [x] audio problems

Release Notes:

- Switch from Swift to Rust LiveKit SDK 🦀

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>
Co-authored-by: Conrad Irwin <conrad@zed.dev>
Co-authored-by: Kirill Bulatov <kirill@zed.dev>
Co-authored-by: Michael Sloan <michael@zed.dev>

crates/gpui/src/platform.rs

@@ -70,6 +70,9 @@ pub(crate) use test::*;
 #[cfg(target_os = "windows")]
 pub(crate) use windows::*;
 
+#[cfg(any(test, feature = "test-support"))]
+pub use test::TestScreenCaptureSource;
+
 #[cfg(target_os = "macos")]
 pub(crate) fn current_platform(headless: bool) -> Rc<dyn Platform> {
     Rc::new(MacPlatform::new(headless))
@@ -149,6 +152,10 @@ pub(crate) trait Platform: 'static {
         None
     }
 
+    fn screen_capture_sources(
+        &self,
+    ) -> oneshot::Receiver<Result<Vec<Box<dyn ScreenCaptureSource>>>>;
+
     fn open_window(
         &self,
         handle: AnyWindowHandle,
@@ -228,6 +235,25 @@ pub trait PlatformDisplay: Send + Sync + Debug {
     }
 }
 
+/// A source of on-screen video content that can be captured.
+pub trait ScreenCaptureSource {
+    /// Returns the video resolution of this source.
+    fn resolution(&self) -> Result<Size<Pixels>>;
+
+    /// Start capture video from this source, invoking the given callback
+    /// with each frame.
+    fn stream(
+        &self,
+        frame_callback: Box<dyn Fn(ScreenCaptureFrame)>,
+    ) -> oneshot::Receiver<Result<Box<dyn ScreenCaptureStream>>>;
+}
+
+/// A video stream captured from a screen.
+pub trait ScreenCaptureStream {}
+
+/// A frame of video captured from a screen.
+pub struct ScreenCaptureFrame(pub PlatformScreenCaptureFrame);
+
 /// An opaque identifier for a hardware display
 #[derive(PartialEq, Eq, Hash, Copy, Clone)]
 pub struct DisplayId(pub(crate) u32);