Also handle mutual recursion in *::getState()

VST3 plugins could freeze in REAPER when the plugin sends
`IComponentHandler::performEdit()` followed by
`IPlugFrame::resizeView()` when REAPER simultaneously tries to call
`*::getState()`. Here `*::getState()` gets called from the GUI thread,
while `IPlugFrame::resizeView()` has to be handled on REAPER's GUI
thread, resulting in a deadlock unless we use the plugin-side mutual
recursion mechanism.

I've seen this cause issues with PSPaudioware InfiniStrip.

CHANGELOG.md

@@ -114,6 +114,9 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 - Fixed _UVI Plugsound Free_ crashing during initialization.
 - Fixed potential freezing when loading a VST3 preset that tries to resize an
   open editor window.
+- Fixed another potential freezing issue in REAPER that could happen when the
+  when the plugin resizes itself while sending a parameter change to the host,
+  if REAPER's 'disable saving full plug-in state' is not disabled.
 - Because of the new transport information prefetching, the excessive DSP usage
   in _SWAM Cello_ is now been fixed without requiring any manual compatibility
   options.