Add missing http.client globals and make all of them literal

[bswck]

Generated with https://gist.github.com/bswck/4b41f8329f602ef7d92e65a8721ec9ae (against typeshed upstream), so I'm pretty sure it doesn't annotate any codes incorrectly.
I discussed the idea of turning these global ints to Literals with @JelleZijlstra.

What's left to do is examine why stubtest allegedly reported no issues with the previous version of the http/client.pyi stub that lacked some constants from runtime.
That's what I'll investigate tomorrow.

[bswck]

BTW, FYI the order of those globals follows exactly the order of which they are originally defined in the enum @ http/__init__.pyi:

typeshed/stdlib/http/__init__.pyi

Lines 17 to 87 in 54e1c6a

	CONTINUE = 100
	SWITCHING_PROTOCOLS = 101
	PROCESSING = 102
	OK = 200
	CREATED = 201
	ACCEPTED = 202
	NON_AUTHORITATIVE_INFORMATION = 203
	NO_CONTENT = 204
	RESET_CONTENT = 205
	PARTIAL_CONTENT = 206
	MULTI_STATUS = 207
	ALREADY_REPORTED = 208
	IM_USED = 226
	MULTIPLE_CHOICES = 300
	MOVED_PERMANENTLY = 301
	FOUND = 302
	SEE_OTHER = 303
	NOT_MODIFIED = 304
	USE_PROXY = 305
	TEMPORARY_REDIRECT = 307
	PERMANENT_REDIRECT = 308
	BAD_REQUEST = 400
	UNAUTHORIZED = 401
	PAYMENT_REQUIRED = 402
	FORBIDDEN = 403
	NOT_FOUND = 404
	METHOD_NOT_ALLOWED = 405
	NOT_ACCEPTABLE = 406
	PROXY_AUTHENTICATION_REQUIRED = 407
	REQUEST_TIMEOUT = 408
	CONFLICT = 409
	GONE = 410
	LENGTH_REQUIRED = 411
	PRECONDITION_FAILED = 412
	if sys.version_info >= (3, 13):
	CONTENT_TOO_LARGE = 413
	REQUEST_ENTITY_TOO_LARGE = 413
	if sys.version_info >= (3, 13):
	URI_TOO_LONG = 414
	REQUEST_URI_TOO_LONG = 414
	UNSUPPORTED_MEDIA_TYPE = 415
	if sys.version_info >= (3, 13):
	RANGE_NOT_SATISFIABLE = 416
	REQUESTED_RANGE_NOT_SATISFIABLE = 416
	EXPECTATION_FAILED = 417
	if sys.version_info >= (3, 13):
	UNPROCESSABLE_CONTENT = 422
	UNPROCESSABLE_ENTITY = 422
	LOCKED = 423
	FAILED_DEPENDENCY = 424
	UPGRADE_REQUIRED = 426
	PRECONDITION_REQUIRED = 428
	TOO_MANY_REQUESTS = 429
	REQUEST_HEADER_FIELDS_TOO_LARGE = 431
	INTERNAL_SERVER_ERROR = 500
	NOT_IMPLEMENTED = 501
	BAD_GATEWAY = 502
	SERVICE_UNAVAILABLE = 503
	GATEWAY_TIMEOUT = 504
	HTTP_VERSION_NOT_SUPPORTED = 505
	VARIANT_ALSO_NEGOTIATES = 506
	INSUFFICIENT_STORAGE = 507
	LOOP_DETECTED = 508
	NOT_EXTENDED = 510
	NETWORK_AUTHENTICATION_REQUIRED = 511
	MISDIRECTED_REQUEST = 421
	UNAVAILABLE_FOR_LEGAL_REASONS = 451
	if sys.version_info >= (3, 9):
	EARLY_HINTS = 103
	IM_A_TEAPOT = 418
	TOO_EARLY = 425

I also assumed the stub is up-to-date with the source, but I'll make sure later.

Also, I think it's reasonable to add a comment like "keep in sync with the http.HTTPStatus enum" here, WDYT?

[AlexWaygood]

What's left to do is examine why stubtest allegedly reported no issues with the previous version of the http/client.pyi stub that lacked some constants from runtime.

If a runtime module explicitly defines __all__, this is understood by stubtest as an explicit statement of "these are the public-API constants; everything else should be understood as private". In general, stubs should only reflect the public API, so if __all__ is defined, stubtest will not complain about anything that is not in __all__ at runtime being missing from the stubs

[bswck]

While checking against the upstream of stdlib, I decided to reorder and reformat both the enum members and the annotated constants to follow exactly the order and format from there.
I also added a note for maintainers/contributors about keeping http.HTTPStatus and http.client.* in sync.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉