Refuse to park a track whose pre-park snapshot is gone, rather than re-snapshotting the already-parked chain as the user's state

src/shell/view/view_fx_park.cpp

@@ -14,6 +14,7 @@
 #define REAPERAPI_MINIMAL
 #define REAPERAPI_WANT_CountTracks
 #define REAPERAPI_WANT_EnumProjects
+#define REAPERAPI_WANT_GetMediaTrackInfo_Value
 #define REAPERAPI_WANT_GetTrack
 #define REAPERAPI_WANT_ShowConsoleMsg
 #define REAPERAPI_WANT_TrackFX_GetCount
@@ -99,6 +100,14 @@ std::string fxGuidString(MediaTrack* tr, int fx) {
 
 }  // namespace
 
+std::vector<int> readParkFlagValues(MediaTrack* tr, const std::vector<TrackFlagOp>& parkFlags) {
+    std::vector<int> live;
+    live.reserve(parkFlags.size());
+    for (const TrackFlagOp& op : parkFlags)
+        live.push_back(static_cast<int>(GetMediaTrackInfo_Value(tr, trackFlagParm(op.flag))));
+    return live;
+}
+
 std::vector<std::string> liveFxGuids(MediaTrack* tr) {
     const int fxCount = TrackFX_GetCount(tr);
     std::vector<std::string> guids;