Make sure rollup output matching input

[jbanety]

An other issue with Rollup output (as #2468).
If my external deps share common code, Rollup will create a chunk with this shared code. That's OK.
But Rollup will add this chunk at the output so import map will be wrong again :

{
  "imports": {
    "@etdsolutions/request": "./chunk-e62c8060.js",
    "single-spa": "./request-627619e8.js",
    "@etdsolutions/stacks": "./single-spa-2080b5a8.js",
    "@etdsolutions/uid": "./stacks-ff183556.js",
    "@fortawesome/free-solid-svg-icons/faChevronUp.js": "./uid-203f014d.js",
    "@fortawesome/free-solid-svg-icons/faChevronDown.js": "./faChevronUp-0ffe90b6.js",
    "bootstrap.native": "./faChevronDown-577c640c.js",
    "@fortawesome/fontawesome-svg-core": "./bootstrap-c17f3a72.js",
    "@etdsolutions/routie": "./fontawesome-svg-core-00332bf4.js",
    "one": "./routie-ad357c93.js",
    "@erp/ui-components/helpers/notify.js": "./one-54bc149a.js",
    "lodash-es/assign.js": "./notify-556a357a.js",
    "lodash-es/clone.js": "./assign-d637c92e.js"
  }
}

Here lodash functions share multiple files.
I fixed that with filtering output array.

[guybedford]

This looks really great, thanks again. Just see the one comment on filter simplification.

I've created a Rollup tracking issue for supporting this natively in rollup/rollup#2868.

[guybedford]

Published in 2.0.0-beta.5.