[Fixes #1761] Add opt-in autogenerate support for check constraints

[jrmalin]

Description

This adds an opt-in compare_check_constraints configuration option for autogenerate, allowing Alembic to detect check constraint differences between SQLAlchemy models and the database.

Changes:

• New config option compare_check_constraints
• Check constraint comparison logic
• Check constraint signature class
• Renderer for CreateCheckConstraintOp
• Comparison method
• Type stub
• Tests covering add, remove, match, disabled, unnamed, invalid names, enum filtering, and bound parameters

Checklist

This pull request is:

• [ ] A documentation / typographical error fix
  • Good to go, no issue or tests are needed
• [ ] A short code fix
  • please include the issue number, and create an issue if none exists, which must include a complete example of the issue. one line code fixes without an issue and demonstration will not be accepted.
  • Please include: Fixes: #<issue number> in the commit message
  • please include tests. one line code fixes without tests will not be accepted.
• [x] A new feature implementation
  • please include the issue number, and create an issue if none exists, which must include a complete example of how the feature would look.
  • Please include: Fixes: #<issue number> in the commit message
  • please include tests.

Have a nice day!