Fixes and adjustments in 3D physics tests

Add Functional Test / Stack & Pyramid
For testing stack stability.

Add Functional Test / Raycasts
Visually test raycast on different shapes.

Add Performance Test / Broadphase
Add/move/remove lots of non-colliding objects and measure time.

Fix leaks on exit
Some Nodes are copied and removed from the scene to be used as templates,
they need to be freed manually on exit.

Fix Performance Test / Contacts
Positions adjusted, some shape types were not created at the center.

3d/physics_tests/utils/container_log.gd

@@ -13,6 +13,10 @@ func _enter_tree():
 	remove_child(_entry_template)
 
 
+func _exit_tree():
+	_entry_template.free()
+
+
 func clear():
 	while get_child_count():
 		var entry = get_child(get_child_count() - 1)