Add a profile for testing postgresql with testcontainers

Create a profile to instantiate a postgresql database with testcontainers in order to execute unit tests with integrated database (not external).
Advantages: db can be easily tuned to the target version of the db for running all community tests with it.

Use of this feature: mvn clean install -Ptc-postgres

Default postgresql db version: 15.3, it can be tuned with -Dpostgres.db.version=15.1

All modules have been tested (including jbpm-test-coverage with -DskipTests=false) but those related to jbpm-container