Rework ECS framework

- Add queue systems when adding/removing components and systems
- Add GlobalData to ECSManager, used to store data that is not specific
  to entities
- Add View class, used to for loop all entities that contains the given
  Components
- Rework how signaling works

CopiumEngine/src/copium/ecs/Entity.cpp

@@ -40,7 +40,7 @@ namespace Copium
     return id != entity.id;
   }
 
-  Entity::operator bool() const
+  bool Entity::IsValid() const
   {
     if (id == INVALID_ENTITY)
       return false;
@@ -49,6 +49,11 @@ namespace Copium
     return false;
   }
 
+  Entity::operator bool() const
+  {
+    return IsValid();
+  }
+
   void Entity::Invalidate()
   {
     id = INVALID_ENTITY;
@@ -79,4 +84,4 @@ namespace Copium
   {
     return {manager, manager->CreateEntity()};
   }
-}
+}