feat: support modifyRouteProps in runtime

[sorrycc]

想到的一些使用场景，这些场景之前用 Routes 也能做，但比较繁琐，而且会多套一层 react 组件。

比如想要访问子路径匹配路由的 match.params 属性，可以在 app.js 下配置，

例子，sorrycc-aRg4p8.zip

import { matchRoutes } from 'react-router-config';

export function modifyRouteProps(memo, { route }) {
  if (/* is layout */route.routes) {
    const m = matchRoutes(route.routes, memo.location.pathname);
    if (m && m.length) {
      memo.match = m[m.length - 1].match;
    }
  }

  return memo;
}

比如实现 title 的 i18n

可以在这一层针对 title 做运行时的转换。

[coveralls]

Pull Request Test Coverage Report for Build 1760

• 2 of 2 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 34.965%

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Totals
Change from base Build 1757:	0.01%
Covered Lines:	1038
Relevant Lines:	3058

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💛 - Coveralls