Fix inherited kwargs rendering for MySQL CHAR collation

[hyoj0942]

Summary

• render inherited initializer kwargs for types whose initializer uses only **kwargs
• preserve MySQL CHAR(..., collation=...) when using keep_dialect_types
• keep behavior bounded to avoid varargs regressions (e.g. SET)

Tests

• PYTHONPATH=src pytest -q tests/test_generator_tables.py -k 'mysql'
• PYTHONPATH=src pytest -q tests/test_generator_declarative.py -k 'keep_dialect_types'

Closes #285.

[coveralls]

coverage: 97.668% (-0.05%) from 97.718%
when pulling 951bf9a on hyoj0942:fix-285-char-collation
into de5adcc on agronholm:master.

[sheinbergon]

Thank you very much for your contribution. Left some cosmetric comments. Don't forget updating CHANGES.rst

[sheinbergon]

@hyoj0942 also notice pre-commit is failing. Be sure to fix linting/formatting/typing issues

[hyoj0942]

@sheinbergon heads-up: I fixed the pre-commit issues and pushed an update (6ef1761). It now passes locally with pre-commit run --all-files.

[sheinbergon]

@sheinbergon heads-up: I fixed the pre-commit issues and pushed an update (6ef1761). It now passes locally with pre-commit run --all-files.

Great. Will be released as part of the next patch version