gh-158886: Add INCREF/DECREF macros to stable_abi.toml (GH-158941)

* Add 7 INCREF/DECREF macros
* distinguish between 'const' and 'macro' in stable_abi.dat
  The file now has the 'kind' from the toml, not the ReST role.
* Fix kind of PY_VECTORCALL_ARGUMENTS_OFFSET
* Make it explicit that macros aren't part of the ABI
* Add is_static_inline_function to the TOML file (these are treated as macros in the docs)


Co-authored-by: Petr Viktorin <encukou@gmail.com>

Author: vstinner