Add DirtyState()/Rework DirtyParametersFromUI()

[olilarkin]

Dumping parameters to sync the dsp side in e.g. VST as is currently done in IPlugVST3::DirtyParametersFromUI() is problematic in some hosts 👀 Live! Causing for example very slow preset changing when clicking through presets in the plugin UI.

something like this is recommend by the VST3 docs, but needs more thought.

Also maybe we need a more generic DirtyState() method

void IPlugController::UpdateProcessorOnPresetRecall()
{
  OPtr<IMessage> message = allocateMessage();
  // check message
  message->setMessageID ("StateDump");
  // dummy code to serialize the state as it exists in the controller
  ByteChunk state;
  SerializeState(&state);
  message->getAttributes ()->setBinary("state", state.GetBytes(), state.Size());
  sendMessage(message);
}

tresult PLUGIN_API IPlugProcessor::notify(IMessage* message)
{  
  if (!message)
    return kInvalidArgument;
  
  if (!strcmp (message->getMessageID(), "StateDump"))
  {
    const void* data;
    Steinberg::uint32 size;
    
    if (message->getAttributes()->getBinary("state", data, size) == kResultOk)
    {
      // dummy code to unserialize the binary state and update the component/processor's parameter values
      ByteChunk chunk;
      chunk.PutBytes(data, size);
      
      int readPos = 0;
      UnserializeState(&chunk, readPos);
    }
  }
  
  return ComponentBase::notify(message);
}