Flask-postgresql-audit

- Forked from PostgreSQL-Audit.
- Rename `VersioningManager` to `PostgreSQLAudit`.
- Drop `__versioned__` attribute pattern in favor of `Audit` mixin class.
- Use `alembic` to make database objects required by pg_audit stateful.
- Utilize `alembic_utils` to generate migration operations.
- Blindly create newly generated database object
to circumvent `alembic_utils` known issue when
object depends on another object in same migration, issue: [41](https://github.com/olirice/alembic_utils/issues/41).
- Update README and LICENSE.

- Fix package name to be in lowercase in `pyproject.toml`.

- Use the `pyproject.toml` standard to specify project metadata,
dependencies and tool configuration. Use Hatch to build the project.
- Make the documentation buildable again.
- Fix some grammar and formatting issues in the documentation
- Refactor `VersioningManager.audit_table()` method and extract the
query building logic into a new method
`VersioningManager.build_audit_table_query()`.
- Fix a deprecation warning about `sqlalchemy.orm.mapper()` symbol
usage on SQLAlchemy 2.0.

- **BREAKING CHANGE**: Drop support for PostgreSQL 9.5, 9.6 and 10,
which have reached end of their lives.
- Add support for SQLAlchemy 2.0
- Remove unused `VersioningManager.cached_ddls` attribute
- Removed redundant statement caching from
`VersioningManager.audit_table`

- **BREAKING CHANGE**: `flask.activity_values` doesn\'t require
request context (75, courtesy of tvuotila)
- **BREAKING CHANGE**: Drop support for Python 3.7
- Fix some SQLAlchemy 2.0 deprecation warnings (76, courtesy of
tchapi)
- Remove unnecessary checks for Flask request context
- Remove unnecessary `__future__` import

- Fix compatibility with Flask-SQLAlchemy\<3.0