feat: merge Encode/DecodeStats into a single PerformanceStats model (#1100)

Author: oliverlaz

protobuf/video/sfu/models/models.pb.go

@@ -401,19 +401,16 @@ enum AppleThermalState {
   APPLE_THERMAL_STATE_CRITICAL = 4;
 }
 
-// EncodeStats represents the encoding statistics for a track.
-message EncodeStats {
+// PerformanceStats represents the encoding/decoding statistics for a track.
+message PerformanceStats {
+  // the type of the track (e.g., video, audio, screen share)
   TrackType track_type = 1;
+  // the codec used for the track
   Codec codec = 2;
-  float avg_frame_encode_time_ms = 3;
-  float avg_fps = 4;
-}
-
-// DecodeStats represents the decoding statistics for a track.
-message DecodeStats {
-  TrackType track_type = 1;
-  Codec codec = 2;
-  float avg_frame_decode_time_ms = 3;
+  // the average encode/decode time in ms
+  float avg_frame_time_ms = 3;
+  // the average fps for the track
   float avg_fps = 4;
+  // the track dimensions
   VideoDimension video_dimension = 5;
 }