Add test for multiple cookies coming from middleware

[Schniz]

This PR adds a test that ensures that we can set multiple cookies in a middleware response

[ijjk]

Holding so this doesn't get auto-merged yet

[javivelasco]

Since it is a test @ijjk can we ship this already?

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
buildDuration	16.7s	17s	⚠️ +245ms
buildDurationCached	6.4s	6.4s	✓
nodeModulesSize	367 MB	367 MB	⚠️ +15 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.085	3.119	⚠️ +0.03
/ avg req/sec	810.28	801.52	⚠️ -8.76
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.462	1.513	⚠️ +0.05
/error-in-render avg req/sec	1709.87	1652.23	⚠️ -57.64

Client Bundles (main, webpack, commons)

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	27.9 kB	27.9 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	71.6 kB	71.6 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
_app-HASH.js gzip	1.36 kB	1.36 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	326 B	326 B	✓
dynamic-HASH.js gzip	2.57 kB	2.57 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	919 B	919 B	✓
image-HASH.js gzip	5.05 kB	5.05 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.26 kB	2.26 kB	✓
routerDirect..HASH.js gzip	321 B	321 B	✓
script-HASH.js gzip	383 B	383 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	14.7 kB	14.7 kB	✓

Client Build Manifests

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
index.html gzip	532 B	532 B	✓
link.html gzip	544 B	544 B	✓
withRouter.html gzip	526 B	526 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
buildDuration	19.9s	19.7s	-236ms
buildDurationCached	6.3s	6.3s	-22ms
nodeModulesSize	367 MB	367 MB	⚠️ +15 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.093	3.41	⚠️ +0.32
/ avg req/sec	808.27	733.22	⚠️ -75.05
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.455	1.45	-0.01
/error-in-render avg req/sec	1718.28	1724.43	+6.15

Client Bundles (main, webpack, commons)

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.1 kB	42.1 kB	✓
main-HASH.js gzip	27.9 kB	27.9 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	71.7 kB	71.7 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	180 B	180 B	✓
amp-HASH.js gzip	305 B	305 B	✓
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.56 kB	2.56 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	911 B	911 B	✓
image-HASH.js gzip	5.08 kB	5.08 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	2.28 kB	2.28 kB	✓
routerDirect..HASH.js gzip	314 B	314 B	✓
script-HASH.js gzip	375 B	375 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	14.7 kB	14.7 kB	✓

Client Build Manifests

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	Schniz/next.js add-test-for-multiple-cookies-in-middleware	Change
index.html gzip	533 B	533 B	✓
link.html gzip	547 B	547 B	✓
withRouter.html gzip	527 B	527 B	✓
Overall change	1.61 kB	1.61 kB	✓

Commit: 8c44ae0