Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-10-02' into staging

QAPI patches patches for 2021-10-02

# gpg: Signature made Sat 02 Oct 2021 01:37:11 AM EDT
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]

* remotes/armbru/tags/pull-qapi-2021-10-02:
  qapi/parser: enable pylint checks
  qapi/parser: Silence too-few-public-methods warning
  qapi/parser: enable mypy checks
  qapi/parser: Add FIXME for consolidating JSON-related types
  qapi/parser: add type hint annotations (QAPIDoc)
  qapi/parser: add import cycle workaround
  qapi/parser: Introduce NullSection
  qapi/parser: clarify _end_section() logic
  qapi/parser: remove FIXME comment from _append_body_line
  qapi: Add spaces after symbol declaration for consistency
  qapi/parser: fix unused check_args_section arguments
  qapi/gen: use dict.items() to iterate over _modules
  qapi/pylintrc: ignore 'consider-using-f-string' warning

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>