Implement db v2 handling

This merge request implements support for V2 of the Database object.

This requires the addition of a new application that handles the new ProtocolTemplate object.

The Database and more specifically the related models handling is updated to that it can continue to work with both version of databases.

It ensures by adding new tests that the execution of experiments still works with both V1 and V2 databases.

Fixes #586 (closed)