Revert "Use livekit's Rust SDK instead of their swift SDK (#13343)" (#20809)

Issues found:

* audio does not work well with various set-ups using USB
* switching audio during initial join may leave the client with no audio
at all
* audio streaming is done on the main thread, beachballing certain
set-ups
* worse screenshare quality (seems that there's no dynamic scaling
anymore, compared to the Swift SDK)

This reverts commit 1235d0808e.

Release Notes:

- N/A

crates/gpui/src/platform/test/platform.rs

@@ -1,7 +1,7 @@
 use crate::{
-    px, size, AnyWindowHandle, BackgroundExecutor, ClipboardItem, CursorStyle, ForegroundExecutor,
-    Keymap, Platform, PlatformDisplay, PlatformTextSystem, ScreenCaptureFrame, ScreenCaptureSource,
-    ScreenCaptureStream, Task, TestDisplay, TestWindow, WindowAppearance, WindowParams,
+    AnyWindowHandle, BackgroundExecutor, ClipboardItem, CursorStyle, ForegroundExecutor, Keymap,
+    Platform, PlatformDisplay, PlatformTextSystem, Task, TestDisplay, TestWindow, WindowAppearance,
+    WindowParams,
 };
 use anyhow::Result;
 use collections::VecDeque;
@@ -31,7 +31,6 @@ pub(crate) struct TestPlatform {
     #[cfg(any(target_os = "linux", target_os = "freebsd"))]
     current_primary_item: Mutex<Option<ClipboardItem>>,
     pub(crate) prompts: RefCell<TestPrompts>,
-    screen_capture_sources: RefCell<Vec<TestScreenCaptureSource>>,
     pub opened_url: RefCell<Option<String>>,
     pub text_system: Arc<dyn PlatformTextSystem>,
     #[cfg(target_os = "windows")]
@@ -39,31 +38,6 @@ pub(crate) struct TestPlatform {
     weak: Weak<Self>,
 }
 
-#[derive(Clone)]
-/// A fake screen capture source, used for testing.
-pub struct TestScreenCaptureSource {}
-
-pub struct TestScreenCaptureStream {}
-
-impl ScreenCaptureSource for TestScreenCaptureSource {
-    fn resolution(&self) -> Result<crate::Size<crate::Pixels>> {
-        Ok(size(px(1.), px(1.)))
-    }
-
-    fn stream(
-        &self,
-        _frame_callback: Box<dyn Fn(ScreenCaptureFrame)>,
-    ) -> oneshot::Receiver<Result<Box<dyn ScreenCaptureStream>>> {
-        let (mut tx, rx) = oneshot::channel();
-        let stream = TestScreenCaptureStream {};
-        tx.send(Ok(Box::new(stream) as Box<dyn ScreenCaptureStream>))
-            .ok();
-        rx
-    }
-}
-
-impl ScreenCaptureStream for TestScreenCaptureStream {}
-
 #[derive(Default)]
 pub(crate) struct TestPrompts {
     multiple_choice: VecDeque<oneshot::Sender<usize>>,
@@ -98,7 +72,6 @@ impl TestPlatform {
             background_executor: executor,
             foreground_executor,
             prompts: Default::default(),
-            screen_capture_sources: Default::default(),
             active_cursor: Default::default(),
             active_display: Rc::new(TestDisplay::new()),
             active_window: Default::default(),
@@ -141,10 +114,6 @@ impl TestPlatform {
         !self.prompts.borrow().multiple_choice.is_empty()
     }
 
-    pub(crate) fn set_screen_capture_sources(&self, sources: Vec<TestScreenCaptureSource>) {
-        *self.screen_capture_sources.borrow_mut() = sources;
-    }
-
     pub(crate) fn prompt(&self, msg: &str, detail: Option<&str>) -> oneshot::Receiver<usize> {
         let (tx, rx) = oneshot::channel();
         self.background_executor()
@@ -233,20 +202,6 @@ impl Platform for TestPlatform {
         Some(self.active_display.clone())
     }
 
-    fn screen_capture_sources(
-        &self,
-    ) -> oneshot::Receiver<Result<Vec<Box<dyn ScreenCaptureSource>>>> {
-        let (mut tx, rx) = oneshot::channel();
-        tx.send(Ok(self
-            .screen_capture_sources
-            .borrow()
-            .iter()
-            .map(|source| Box::new(source.clone()) as Box<dyn ScreenCaptureSource>)
-            .collect()))
-            .ok();
-        rx
-    }
-
     fn active_window(&self) -> Option<crate::AnyWindowHandle> {
         self.active_window
             .borrow()
@@ -375,13 +330,6 @@ impl Platform for TestPlatform {
     }
 }
 
-impl TestScreenCaptureSource {
-    /// Create a fake screen capture source, for testing.
-    pub fn new() -> Self {
-        Self {}
-    }
-}
-
 #[cfg(target_os = "windows")]
 impl Drop for TestPlatform {
     fn drop(&mut self) {