Use DTOs and disable openentityinview

[mpostelnicu]

Use DTOs (with MapStruct) to map to DAOs and connect to database level. This will:

• remove any hibernate session dependencies from UI
• allow us to turn openentityinview to off. Openentityinview is considered anti-pattern
• never get lazy initializer errors in the UI
• clear separation of persistence and UI logic
• remove dozer hibernate model - which is currently unmaintained and relies heavily on hibernate specific api
• aim to be JPA 2.2+ compliant, without specific Hibernate bindings. This will allow us to choose other ERMs than Hibernate, like EclipseLink, DataNucleus, etc...