🐛 Don't break references when updating a port

lib/utils.dart

@@ -0,0 +1,14 @@
+import 'package:gomix_flutter/mixer_state.dart' as mixer;
+
+mixer.Port? findPort(mixer.MixerState mixerState, String uuid) {
+  int index = mixerState.inputs.indexWhere((element) => element.uuid == uuid);
+  if (index >= 0) {
+    return mixerState.inputs[index];
+  }
+  index = mixerState.outputs.indexWhere((element) => element.uuid == uuid);
+  if (index >= 0) {
+    return mixerState.outputs[index];
+  }
+
+  return null;
+}