Feature: Adding Scene and Object to the Gamium Path

[harryplusplus]

Problem

1. Scene, DonDestroyOnLoad and New UI System corresponding to Scene cannot be inquired in the form of Gamium Path.
2. In xpath, if you don't have the same type of sibling, you don't have to approach index.
   Even if you don't have a sibling with the same name in GamiumPath, you should approach index.

Solution brainstorm

hierarchy
  MyScene
    MyGameObject
    MyGameObject
    MyOtherObject
  DontDestroyOnLoad
  VisualElement
    MyVisualElement

In the case of the above structure, I think you should be able to search with the GamiumPath below.

/MyScene/MyGameObject[1]
/MyScene/MyGameObject[2]
/MyScene/MyOtherObject
/VisualElement/MyVisualElement