Modify `_http_outgoing.ts` to support the extended signature of
`validateHeaderName()` used since node v19.5.0/v18.14.0 by adding the
`label` parameter. (see:
https://nodejs.org/api/http.html#httpvalidateheadernamename-label)
Making both validation functions accessible as public exports of
`node:http`
Fixes: #22614
Note: tests are not the only part of the codebase that uses `std`. Other
parts, like `tools/`, do too. So, it could be argued that this is a
little misleading. Either way, I'm doing this as discussed with
@mmastrac.
This looks like a massive PR, but it's only a move from cli/tests ->
tests, and updates of relative paths for files.
This is the first step towards aggregate all of the integration test
files under tests/, which will lead to a set of integration tests that
can run without the CLI binary being built.
While we could leave these tests under `cli`, it would require us to
keep a more complex directory structure for the various test runners. In
addition, we have a lot of complexity to ignore various test files in
the `cli` project itself (cargo publish exclusion rules, autotests =
false, etc).
And finally, the `tests/` folder will eventually house the `test_ffi`,
`test_napi` and other testing code, reducing the size of the root repo
directory.
For easier review, the extremely large and noisy "move" is in the first
commit (with no changes -- just a move), while the remainder of the
changes to actual files is in the second commit.
