Add withInitScripts to the SQL database modules #1574

What happens

None of the SQL database modules has a way to run a schema or seed script at startup. Their builder methods are limited to credentials and the database name:

Users copy files into the image's init directory themselves, which means knowing that directory for each image:

new PostgreSqlContainer(image).withCopyFilesToContainer([
  { source: "./schema.sql", target: "/docker-entrypoint-initdb.d/schema.sql" },
]);

For images with no init directory (SQL Server), it means running the script with exec after start.

Expected

withInitScripts(...paths) on each SQL module, run in the order given, using the image's init directory where there is one and the database's CLI otherwise.

Where

packages/modules/{postgresql,mysql,mariadb,mssqlserver,cockroachdb,clickhouse,oraclefree}/src.

Notes

• Java has withInitScript and withInitScripts on JdbcDatabaseContainer, shared by every JDBC module. Go has WithInitScripts and WithOrderedInitScripts on postgres and WithScripts on mysql.
• Each module is an independent change.

Dependencies

• Nothing blocks this. It can start now.
• Coordinate with Converge connection getter and command helper names across modules #1538: for the method name.