Widgets: Improve theme

- move simple styles classes ton their own file
- add button hovered texture
- add button hovered/pressed texture
- add label style

src/Nazara/Widgets/WidgetTheme.cpp

@@ -3,6 +3,8 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/Widgets/WidgetTheme.hpp>
+#include <Nazara/Graphics/Components/GraphicsComponent.hpp>
+#include <Nazara/Utility/Components/NodeComponent.hpp>
 #include <Nazara/Widgets/Canvas.hpp>
 #include <Nazara/Widgets/Debug.hpp>
 
@@ -12,11 +14,23 @@ namespace Nz
 
 	BaseWidgetStyle::~BaseWidgetStyle() = default;
 
+	entt::entity BaseWidgetStyle::CreateGraphicsEntity()
+	{
+		auto& registry = GetRegistry();
+
+		entt::entity entity = CreateEntity();
+		registry.emplace<GraphicsComponent>(entity, m_widgetOwner->IsVisible());
+		registry.emplace<NodeComponent>(entity).SetParent(m_widgetOwner);
+
+		return entity;
+	}
+
 	UInt32 BaseWidgetStyle::GetRenderMask() const
 	{
 		return m_widgetOwner->GetCanvas()->GetRenderMask();
 	}
 
+
 	void ButtonWidgetStyle::OnHoverBegin()
 	{
 	}
@@ -32,4 +46,13 @@ namespace Nz
 	void ButtonWidgetStyle::OnRelease()
 	{
 	}
+
+
+	void LabelWidgetStyle::OnHoverBegin()
+	{
+	}
+
+	void LabelWidgetStyle::OnHoverEnd()
+	{
+	}
 }