bug: exports map key with star in the middle doesn't work

[dummdidumm]

enhanced-resolve can't deal with stars in the middle of a key of an exports map. It's allowed though (see subpath patterns).

{
	"exports": {
		"./foo/*.js": "./foo/*.js"
	}
}

To fix it I suggest to replace most of the current implementation around import and export maps with resolve.exports, a widely-used npm package which aims to consolidate resolving export maps across tooling. It would potentially mean to get rid of some of the validation errors this plugin throws when encountering invalid export maps. I'm not sure if you want that, or to what extend.

[dummdidumm]

Closing as duplicate of #352