Inspector: Show remote object properties in a table view

This patch expands the object model of this program quite a bit.
We now have a RemoteProcess object that contains a list of remote root
RemoteObject objects.

The RemoteProcess vends a RemoteObjectGraphModel&, and indices in that
model have internal_data() pointing to a corresponding RemoteObject.
RemoteObjects in turn vend a RemoteObjectPropertyModel&, which is what
we use to show the object properties.

This is pretty cool :^)

DevTools/Inspector/RemoteObjectPropertyModel.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <AK/JsonValue.h>
+#include <LibGUI/GModel.h>
+
+class RemoteObject;
+
+class RemoteObjectPropertyModel final : public GModel {
+public:
+    virtual ~RemoteObjectPropertyModel() override {}
+    static NonnullRefPtr<RemoteObjectPropertyModel> create(RemoteObject& object)
+    {
+        return adopt(*new RemoteObjectPropertyModel(object));
+    }
+
+    enum Column {
+        Name,
+        Value,
+        __Count,
+    };
+
+    virtual int row_count(const GModelIndex& = GModelIndex()) const override;
+    virtual int column_count(const GModelIndex& = GModelIndex()) const override { return Column::__Count; }
+    virtual String column_name(int) const override;
+    virtual GVariant data(const GModelIndex&, Role = Role::Display) const override;
+    virtual void update() override;
+
+private:
+    explicit RemoteObjectPropertyModel(RemoteObject&);
+
+    RemoteObject& m_object;
+    struct NameAndValue {
+        JsonValue name;
+        JsonValue value;
+    };
+    Vector<NameAndValue> m_properties;
+};