[PATCH v3 0/8] qapi: static typing conversion, pt4

[John Snow]

Hi, this series adds static type hints to the QAPI module.
This is part four, and focuses on error.py.

Part 4: https://gitlab.com/jsnow/qemu/-/tree/python-qapi-cleanup-pt4
CI: https://gitlab.com/jsnow/qemu/-/pipelines/290152364

Requirements:
- Python 3.6+
- mypy >= 0.770
- pylint >= 2.6.0 (2.7.0+ when using Python 3.9+)

Every commit should pass with:
 - `isort -c qapi/`
 - `flake8 qapi/`
 - `pylint --rcfile=qapi/pylintrc qapi/`
 - `mypy --config-file=qapi/mypy.ini qapi/`

V3:

```
001/8:[down]      'qapi/error: Repurpose QAPIError as an abstract base 
exception class'
002/8:[----] [--] 'qapi/error: Use Python3-style super()'
003/8:[----] [--] 'qapi/error: Make QAPISourceError 'col' parameter optional'
004/8:[down]      'qapi/error: assert QAPISourceInfo is not None'
005/8:[0010] [FC] 'qapi/error.py: move QAPIParseError to parser.py'
006/8:[----] [--] 'qapi/error.py: enable pylint checks'
007/8:[----] [-C] 'qapi/error: Add type hints'
008/8:[----] [--] 'qapi/error.py: enable mypy checks'
```

- 01: Updated commit message. (Is it sufficient to pass the sniff test?)
- 04: Changed commit title/message.
- 05: Added a small docstring (I know, hubris again) to add a small
      breadcrumb to the new error location for QAPIParseError.

John Snow (8):
  qapi/error: Repurpose QAPIError as an abstract base exception class
  qapi/error: Use Python3-style super()
  qapi/error: Make QAPISourceError 'col' parameter optional
  qapi/error: assert QAPISourceInfo is not None
  qapi/error.py: move QAPIParseError to parser.py
  qapi/error.py: enable pylint checks
  qapi/error: Add type hints
  qapi/error.py: enable mypy checks

 docs/sphinx/qapidoc.py |  3 ++-
 scripts/qapi/error.py  | 47 ++++++++++++++++++++++++------------------
 scripts/qapi/mypy.ini  |  5 -----
 scripts/qapi/parser.py | 14 ++++++++++++-
 scripts/qapi/pylintrc  |  3 +--
 scripts/qapi/schema.py |  4 ++--
 6 files changed, 45 insertions(+), 31 deletions(-)

-- 
2.30.2