I would like the Height to be scaled according to the children

## Describe the feature

I saw that there are numerous issues saying that the height of the PagerView is not according to the height of the children. I wish it was. Is it possible to implement this in the current source code architecture? Is there any direction? I would like to do a PR with this, but first I wanted to know if it's possible.

I saw the workarounds and in my use case they are not enough.

## Motivation

I have several pages that have varying sizes. I use LazyPagerView from the new Pre-Release version, so I can't consider the highest height of the first pages.

## Related Issues

https://github.com/callstack/react-native-pager-view/issues/436
https://github.com/callstack/react-native-pager-view/issues/386

まず、現在の PagerView と LazyPagerView の実装、および関連する issue #436 と #386 を確認します。既存のアーキテクチャで子要素ごとに異なる高さを測定できるかどうかを判断し、対応しているプラットフォームでは PagerView の高さが現在表示されている子要素に合わせて変わることを完了条件として定義します。

索引モデルが issue の本文から書いたものです。