Set up the VST3 Root Until so vst3 validator succeeds (#128)

Set up all the IDs required to get a valid root unit in the
steinberg validator. Addresses #118

src/wrapasvst3.cpp

@@ -461,7 +461,6 @@ Vst::UnitID ClapAsVst3::getOrCreateUnitInfo(const char* modulename)
     }
     else
     {
-      // the unit needs to be created
       Steinberg::Vst::String128 name;
       std::string u8name(path[i]);
       if (VST3::StringConvert::convert(u8name, name))
@@ -581,10 +580,14 @@ void ClapAsVst3::setupParameters(const clap_plugin_t* plugin, const clap_plugin_
   units.clear();
 
   {
-    Vst::String128 rootname(STR16("root"));
-    Vst::Unit* newunit = new Vst::Unit(rootname, Vst::kNoParentUnitId,
-                                       Vst::kRootUnitId);  // a new unit without a program list
-    addUnit(newunit);
+    Vst::UnitInfo rootInfo;
+    rootInfo.id = Vst::kRootUnitId;
+    rootInfo.parentUnitId = Vst::kNoParentUnitId;
+    rootInfo.programListId = Vst::kNoProgramListId;
+    VST3::StringConvert::convert(std::string("Root"), rootInfo.name);
+
+    auto rootUnit = new Vst::Unit(rootInfo);
+    addUnit(rootUnit);
   }
 
   auto numparams = params->count(plugin);