Nnnn data bind fixes part 3

This PR is mostly about handling pointers between dart and rive_native.
All data binding classes are now wrapped in a reference counted class to make sure that there are no unhandled pointers.

Diffs=
d3f6a49778 Nnnn data bind fixes part 3 (#8663)

Co-authored-by: hernan <hernan@rive.app>

.rive_head

@@ -1 +1 @@
-baf832a6ce3135bc7f8f8b5cc3695f024610b744
+d3f6a49778aa6ce7408aecededeb1afc1bf33e6e

include/rive/viewmodel/viewmodel_instance.hpp

@@ -14,6 +14,7 @@ class ViewModelInstance : public ViewModelInstanceBase
     ViewModel* m_ViewModel;
 
 public:
+    ~ViewModelInstance();
     void addValue(ViewModelInstanceValue* value);
     ViewModelInstanceValue* propertyValue(const uint32_t id);
     ViewModelInstanceValue* propertyValue(const std::string& name);

include/rive/viewmodel/viewmodel_instance_viewmodel.hpp

@@ -11,6 +11,7 @@ class ViewModelInstanceViewModel : public ViewModelInstanceViewModelBase
     ViewModelInstance* m_referenceViewModelInstance;
 
 public:
+    ~ViewModelInstanceViewModel();
     void referenceViewModelInstance(ViewModelInstance* value)
     {
         m_referenceViewModelInstance = value;

src/viewmodel/viewmodel_instance.cpp

@@ -11,6 +11,14 @@
 
 using namespace rive;
 
+ViewModelInstance::~ViewModelInstance()
+{
+    for (auto value : m_PropertyValues)
+    {
+        delete value;
+    }
+}
+
 void ViewModelInstance::addValue(ViewModelInstanceValue* value)
 {
     m_PropertyValues.push_back(value);

src/viewmodel/viewmodel_instance_viewmodel.cpp

@@ -6,6 +6,11 @@
 
 using namespace rive;
 
+ViewModelInstanceViewModel::~ViewModelInstanceViewModel()
+{
+    delete m_referenceViewModelInstance;
+}
+
 void ViewModelInstanceViewModel::setRoot(ViewModelInstance* value)
 {
     Super::setRoot(value);