Create a common schema for testing

[DavideD]

The update of a schema is a pretty heavy operation, in particular for databases like CockroachDB.
For testing we re-create a schema almost every time we launch a test.

An idea to explore is to have a set of entities that cover most of testing scenarios and try to reuse this schema everytime we add a new test. This way we could create a new schema at the beginning of the test phase and reuse it for all the tests.

It something that needs to be explored and it's probably related, or might make it obsolete, to #487

[blafond]

@DavideD

Chatted with @sebersole a bit today.

Looks like ORM has added session factory management and common schema in the wip/6.0 branch using junit annotations including @DomainModel for entity management and @SessionFactory.

Not sure if there is a common schema though.

[sebersole]

There is a series of common schemas. A single one is just not feasible.

[DavideD]

Thanks @sebersole.

It would be nice if we could reuse something or adapt it for reactive