OGM-440 Remove incorrect call to setNamingStrategy in Integrator

Also mutualize initialization code
OGM-21 Support EntityManager#createQuery(String)
OGM-21 Test case for OgmEntityManager#createQuery(String)
OGM-14 Support TypedQuery in OgmEntityManager
OGM-14 Add tests for TypedQuery in OgmEntityManager
OGM-15 Test support for EntityManager#createNamedQueries
OGM-15 Support for EntityManager#createNamedQueries
OGM-14 Support for TypedQuery EntityManager#createNamedQueries