[PATCH v2 0/4] MR8696: widl: Cleanup write_type helpers (1/3).

[Rémi Bernon (＠rbernon)]

Patches taken from !6207, no-op but should make the `write_type` helpers more readable and flexible.

--
  v2: widl: Move some type name construction out of write_type_left.
      widl: Remove unnecessary recursion for TYPE_BITFIELD.
      widl: Introduce a new append_basic_type helper.
      widl: Wrap strappend parameters in a new struct strbuf.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8696