feat:simplify route file

[Xy2002]

Integrated router generation plug-in and configuration support, and implemented the function of simplifying routing files

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC.
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests and other checks with pnpm ci

Changesets

• If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running pnpm changeset and following the prompts. Changesets that add features and fix bugs should all be patch before we release 0.1.0. Please prefix changeset messages with feat:, fix:, or chore:.

Edits

• Please ensure that 'Allow edits from maintainers' is checked. PRs without this option may be closed.

[changeset-bot]

🦋 Changeset detected

Latest commit: 199ecd8

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[Xy2002]

目前实现的效果为：

首先在 .tnfrc.ts 文件里，通过 router.routeFileSimplify 启用该功能，然后就可以直接在页面文件里，使用 export default 导出页面组件，同时 router.convention 会自动传入，作为 tanstack router 插件的配置。

移植过的 tanstack router 插件会自动在 .tnf 目录下，生成对应 pages 目录结构的中间文件，然后通过插件自动补全中间文件的内容，再对中间文件进行更改，将原本的页面组件进行导入，以替换插件自动生成的组件，完成简化路由的目的。

并且可以正常使用loader等功能，用户可以在 .tnf/pages 目录下对中间文件进行修改，页面文件变动不会直接覆盖掉生成好的中间文件。

example:

// src/pages/foo.tsx

export default function Foo() {
  return <div>Foo</div>
}

// .tnf/pages/foo.tsx

import ImportComponent from '../../src/pages/foo'
import { createFileRoute } from '@umijs/tnf/router'

export const Route = createFileRoute('/foo')({
  component: ImportComponent,
})