Add support for Oracle Free, the replacement for Oracle XE, with Testcontainers and Docker Compose

[philwebb]

See spring-io/start.spring.io#1352, specifically this comment

[wilkinsona]

Re-opening to investigate the test failures on CI:

 ORA-12514: Cannot connect to database. Service xepdb1 is not registered with the listener at host 127.0.0.1 port 32783. (CONNECTION_ID=iOW0NRoUQq2zqe2ckHsYEw==)