SQLAlchemy 2.0 ComponentReflectionTest test_check_constraint_standalone fails

[kadler]

pyodbc.Error: ('HY000', '[HY000] [IBM][System i Access ODBC Driver][DB2 for i5/OS]SQL5051 - Qualifier SQLALCHEMY not same as name TEST_SCHEMA. (-5051) (SQLExecDirectW)')

This is caused by the constraint name not being schema-qualified and the table schema doesn't match the default schema:

CREATE TABLE test_schema.sa_cc (
        a INTEGER, 
        CONSTRAINT "MyCkConst" CHECK (a = 1 OR (a > 2 AND a < 5))
)

We will have to modify DB2IdentifierPreparer to override the format_constraint function which adds the schema.

See https://github.com/sqlalchemy/sqlalchemy/blob/0c6e2f39df1e6748a916fc5f5a1a3b3296aed4af/lib/sqlalchemy/sql/compiler.py#L8219-L8222 for how to get the schema and default format_constraint is https://github.com/sqlalchemy/sqlalchemy/blob/0c6e2f39df1e6748a916fc5f5a1a3b3296aed4af/lib/sqlalchemy/sql/compiler.py#L8133