Custom AutoImport

Settings example:

{
	"customAutoImport": {
		"imports": {
			"_": "lodash",
			"{ flatMap }": "lodash",
			"{ filter as _filter }": "lodash",
			"{ useMemo, useCallback, useEffect }": "react",
			"MySomething": "@myprefix/mylib/something"
		}
	}
}

Then, autocomplete will offer to autoimport lodash as _, or _filter as alias to filter from lodash.

Currently, autoimport just inserts string like:

import MySomething from '@myprefix/mylib/something';

to the top of file and tries to add { nonDefault } to the existing import.

It is enough for me, but I'm open for issues.