Add jest watch-typeahead plugin

[serkanyersen]

What problem does this feature solve?

Jest lost it's typeahead mode due to some licensing problem. jestjs/jest#4931

This was a very useful feature for jest. Jest community later brought it back as a plugin https://github.com/jest-community/jest-watch-typeahead

It would be nice if vue-cli jest comes bundled with this plugin.

What does the proposed API look like?

it should be as simple as installing the plugin and adding

watchPlugins: [
    'jest-watch-typeahead/filename',
    'jest-watch-typeahead/testname',
],

in the jest.config.js file.

I can provide a PR for this is you like.

[haoqunjiang]

I think it is the time to add this plugin now that jest-community/jest-watch-typeahead#20 is resolved.