fix(ts): match MiddlewareConfig with documentation

[balazsorban44]

What?

Fix the user-facing MiddlewareConfig interface.

While in the codebase, I also made the incoming config object type a bit more strict by converting from any to unknown. Reverted, as we do a config assertion already in a different place.

Why?

The interface we previously exposed was the one we used internally, after we did some parsing on the config object, which is different from what the user is expected to pass.

How?

I separated the internal type to its own MiddlewareConfigParsed interface.

Closes NEXT-2375
Fixes #61705

Ref: #61576

[ijjk]

Tests Passed

[ijjk]

Stats from current PR

Default Build

General Overall increase ⚠️

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
buildDuration	11.7s	11.7s	N/A
buildDurationCached	6s	5.4s	N/A
nodeModulesSize	196 MB	196 MB	⚠️ +1.02 kB
nextStartRea..uration (ms)	435ms	428ms	N/A

Client Bundles (main, webpack)

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
3f784ff6-HASH.js gzip	53.4 kB	53.4 kB	✓
423.HASH.js gzip	185 B	181 B	N/A
68-HASH.js gzip	29.8 kB	29.8 kB	N/A
framework-HASH.js gzip	45.2 kB	45.2 kB	✓
main-app-HASH.js gzip	238 B	240 B	N/A
main-HASH.js gzip	31.8 kB	31.8 kB	N/A
webpack-HASH.js gzip	1.7 kB	1.7 kB	✓
Overall change	100 kB	100 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
_app-HASH.js gzip	194 B	195 B	N/A
_error-HASH.js gzip	182 B	181 B	N/A
amp-HASH.js gzip	502 B	501 B	N/A
css-HASH.js gzip	320 B	322 B	N/A
dynamic-HASH.js gzip	2.5 kB	2.5 kB	N/A
edge-ssr-HASH.js gzip	255 B	256 B	N/A
head-HASH.js gzip	350 B	349 B	N/A
hooks-HASH.js gzip	368 B	369 B	N/A
image-HASH.js gzip	4.19 kB	4.18 kB	N/A
index-HASH.js gzip	257 B	256 B	N/A
link-HASH.js gzip	2.61 kB	2.61 kB	N/A
routerDirect..HASH.js gzip	310 B	311 B	N/A
script-HASH.js gzip	384 B	383 B	N/A
withRouter-HASH.js gzip	306 B	308 B	N/A
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Overall change	106 B	106 B	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
_buildManifest.js gzip	483 B	484 B	N/A
Overall change	0 B	0 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
index.html gzip	529 B	527 B	N/A
link.html gzip	541 B	538 B	N/A
withRouter.html gzip	524 B	522 B	N/A
Overall change	0 B	0 B	✓

Edge SSR bundle Size

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
edge-ssr.js gzip	94 kB	94.1 kB	N/A
page.js gzip	149 kB	149 kB	N/A
Overall change	0 B	0 B	✓

Middleware size

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
middleware-b..fest.js gzip	622 B	623 B	N/A
middleware-r..fest.js gzip	151 B	149 B	N/A
middleware.js gzip	37.7 kB	37.7 kB	N/A
edge-runtime..pack.js gzip	1.92 kB	1.92 kB	✓
Overall change	1.92 kB	1.92 kB	✓

Next Runtimes

	vercel/next.js canary	vercel/next.js fix/middleware-config-type	Change
app-page-exp...dev.js gzip	166 kB	166 kB	✓
app-page-exp..prod.js gzip	95.1 kB	95.1 kB	✓
app-page-tur..prod.js gzip	96.9 kB	96.9 kB	✓
app-page-tur..prod.js gzip	91.4 kB	91.4 kB	✓
app-page.run...dev.js gzip	135 kB	135 kB	✓
app-page.run..prod.js gzip	90 kB	90 kB	✓
app-route-ex...dev.js gzip	22 kB	22 kB	✓
app-route-ex..prod.js gzip	14.8 kB	14.8 kB	✓
app-route-tu..prod.js gzip	14.8 kB	14.8 kB	✓
app-route-tu..prod.js gzip	14.6 kB	14.6 kB	✓
app-route.ru...dev.js gzip	21.7 kB	21.7 kB	✓
app-route.ru..prod.js gzip	14.6 kB	14.6 kB	✓
pages-api-tu..prod.js gzip	9.43 kB	9.43 kB	✓
pages-api.ru...dev.js gzip	9.7 kB	9.7 kB	✓
pages-api.ru..prod.js gzip	9.43 kB	9.43 kB	✓
pages-turbo...prod.js gzip	22 kB	22 kB	✓
pages.runtim...dev.js gzip	22.7 kB	22.7 kB	✓
pages.runtim..prod.js gzip	22 kB	22 kB	✓
server.runti..prod.js gzip	49.7 kB	49.7 kB	✓
Overall change	922 kB	922 kB	✓

Commit: d074b07