hierachy and parent child system updates

- started working on an editor hierarchy window
- testing filters
- testing parent child relations without system
- testing root component
- thinking about how to get all entities that are not a child, but also don't have an other identifying component

Nerfed.Runtime/Components/Parent.cs

@@ -2,7 +2,10 @@
 
 namespace Nerfed.Runtime.Components
 {
-    public readonly record struct Parent(Entity parentEntity);
-    public readonly record struct PreviousParent(Entity parentEntity);
-    public readonly record struct ChildRelation;
+    public readonly record struct Root;
+    //public readonly record struct Parent;
+    //public readonly record struct PreviousParent;
+    public readonly record struct Child;
+    // Describes a relation from the child to the parent.
+    public readonly record struct ChildParentRelation;
 }

Nerfed.Runtime/Components/Test.cs

@@ -0,0 +1,4 @@
+namespace Nerfed.Runtime.Components
+{
+    public readonly record struct Test();
+}