Add human readable name for effGetTailSize opcode

src/common/vst24.h

@@ -47,6 +47,12 @@
 [[maybe_unused]] constexpr int effSetSpeakerArrangement = 42;
 [[maybe_unused]] constexpr int effGetSpeakerArrangement = 69;
 
+/**
+ * Used by hosts to query the length of reverb tails (equivalent to
+ * `IAudioProcessor::getTailSamples`). Found on the same list as above.
+ */
+[[maybe_unused]] constexpr int effGetTailSize = 52;
+
 /**
  * The struct that's being passed through the data parameter during the
  * `effGetInputProperties` and `effGetOutputProperties` opcodes. Reverse