Bug 1844 - Nyquist effects move subsequent envelope points by selection's length

Also renamed Envelop::Paste to Envelope::PasteEnvelope, since it was hard to find
just its usages, given the many usages of WaveTrack::Paste.

src/TimeTrack.cpp

@@ -124,7 +124,7 @@ void TimeTrack::Paste(double t, const Track * src)
       return;
 
    auto sampleTime = 1.0 / GetActiveProject()->GetRate();
-   mEnvelope->Paste
+   mEnvelope->PasteEnvelope
       (t, static_cast<const TimeTrack*>(src)->mEnvelope.get(), sampleTime);
 }