大量字段场景下的表格/表单性能差

#### 描述问题：

大量字段场景下的表格/表单性能差. 在渲染完成后, 在一个 Input 中输入响应很慢.

#### 如何复现（请务必完整填写下面内容）：

1. 你是如何使用 amis 的？
`npm`

2. amis 版本是什么？请先在最新 beta 版本测试问题是否存在
1.5.3

3. 粘贴有问题的完整 `amis schema` 代码：
20*20 的表格表单输入时非常卡顿.

```
const AmisTable = () => {
return renderAmis({
type: 'page',
body: {
type: 'form',
data: {
table: Array.from({ length: 20 }).map((_, i) => ({})),
},
body: [
{
showIndex: true,
type: 'input-table',
name: 'table',
label: 'Table',
addable: true,
needConfirm: false,
columns: Array.from({ length: 20 }).map((_, i) => ({
label: `A_${i}`,
name: `a_${i}`,
type: 'input-text',
})),
},
],
},
});
};

const Amis = () => {
return renderAmis({
type: 'page',
body: {
type: 'form',
api: 'https://3xsw4ap8wah59.cfc-execute.bj.baidubce.com/api/amis-mock/mock2/form/saveForm',
body: Array.from({ length: LENGTH }).map((_, i) => {
return {
type: 'input-text',
name: `name_${i}`,
label: `name_${i}`,
};
}),
},
});
};
```


Start with the supplied AmisTable and Amis reproductions using the reported 1.5.3 setup, then profile input handling and rendering while typing in the 20×20 cases. Done means a single input remains responsive in both the large-table and large-form scenarios, with coverage for the reproduction.

Written by the indexing model from the issue text.