Unity/R3/UniRxから移植

using置換

- using UniRx;
+ using R3;
- using UniRx.Triggers;
+ using R3.Triggers;
- using System;

参考：https://zenn.dev/tkada/articles/a96258e080056a

ObserveEveryValueChangedはEveryValueChangedへ

// UniRx
transform.ObserveEveryValueChanged(_ => _.Count).Subscribe(count => Debug.Log(count));

// R3
Observable.EveryValueChanged(transform, _ => _.Count)
     .Subscribe(count => Debug.Log(count));

参考：https://qiita.com/toRisouP/items/4344fbcba7b7e8d8ce16