fix(http): reject unsupported codecs with 415 and the codec as body

crates/server/src/http.rs

@@ -63,7 +63,7 @@ pub struct ServerInfo {
 
 pub struct HttpServer {
     pub offer_tx: Sender<(i32, i32, String)>,
-    pub accept_rx: async_broadcast::InactiveReceiver<(i32, Option<String>)>,
+    pub accept_rx: async_broadcast::InactiveReceiver<(i32, Result<String, String>)>,
     pub appstate: Arc<Mutex<AppState>>,
     pub request_count: AtomicI32,
     pub db: DatabaseConnection,
@@ -456,18 +456,15 @@ async fn stream_handler(
     })
     .await
     {
-        Ok(Some(Some(reply))) => {
+        Ok(Some(Ok(reply))) => {
             return Ok(Response::builder()
                 .status(StatusCode::CREATED)
                 .header("content-type", "application/sdp")
                 .body(reply)
                 .unwrap());
         }
-        Ok(Some(None)) => {
-            return Ok(Response::builder()
-                .status(StatusCode::UNSUPPORTED_MEDIA_TYPE)
-                .body(String::new())
-                .unwrap());
+        Ok(Some(Err(codec))) => {
+            return Err(HttpError::WhepCodecError(codec));
         }
         Ok(None) => {
             info!(