PluginParameterSet ctor waits on async thread start
PluginParameterSet ctor waits on async thread start

Construction must occur synchronously, this class must guarantee that
it is ready to process data on either thread before returning.
Otherwise, unexpected behavior can occur if parameter changes or
destruction occurs directly after instantiation.

teragonaudio/PluginParameters,alessandrostone/PluginParameters,teragonaudio/PluginParameters,alessandrostone/PluginParameters