feat: support non-configurable responses

[kettanaito]

[!WARNING] A breaking change since isResponseWithoutBody utility is no longer exported from the package's root. Use FetchResponse.isResponseWithBody (notice inversion) instead.

• Fixes https://github.com/mswjs/msw/issues/2307

Motivation

Mostly to support passthrough responses like 101 Switching Protocols that happen in the apps that use WebSockets. Technically, also unblocks mocking non-configurable responses, but you have to use custom logic to make that happen (since new Response() will still throw per spec).

• [x] ClientRequest
• [x] XMLHttpRequest
• [x] fetch
• [x] RemoteHttpInterceptor

Note: In tests, I'm often constructing a 101 response without upgrade, which is technically invalid. The issue is, I don't want to bring the way request clients handle upgrades themselves to tests because that's not the point. Interceptors just has to ensure the non-configurable response status codes are supported from the original server and from the mocks.

[kettanaito]

Released: v0.37.0 🎉

This has been released in v0.37.0!

• 📄 Release notes
• 📦 npm package

Make sure to always update to the latest version (npm i @mswjs/interceptors@latest) to get the newest features and bug fixes.

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