GeezerVison

Fixes the Sphinx nit-picky reference warnings for
Doc/library/http.cookiejar.rst and Doc/library/http.server.rst, and
removes both files from Doc/tools/.nitignore so future regressions are
caught by CI.

Approach:

• Documented targets are qualified with their owning class, e.g.
  Cookie.version, CookiePolicy.rfc2965/hide_cookie2, the
  urllib.request.Request methods and attributes, and
  urllib.response.addinfourl.info.
• References with no documented target become inline literals: the removed
  get_origin_req_host method, and the undocumented http.server members
  server_name, server_port, list_directory, guess_type and
  index_pages. I'm happy to document any of these instead if a reviewer
  prefers.

Verified with a full nit-picky docs build: both files now emit zero
warnings, and Doc/tools/check-warnings.py --fail-if-regression --fail-if-improved passes.

Documentation-only reference fix, so no Misc/NEWS.d entry (skip news).

Disclosure: I used AI assistance on this change; I've reviewed it and can
explain it.

• Issue: Fix all Sphinx reference warnings in Doc/library/http.{cookiejar,server}.rst #151945