Add decorator for controllers exception management

Added a decorator which manages wsme exceptions by raising a wsme
ClientSideError if a SolumException is thrown.

Change-Id: Id92df3fbbab9245c52b1d8da3ce52b07b0f55a77
Refactor of sqlalchemy objects unit tests

Refactored the code that inserts sqlalchemy objects from static data
into a generic method available in utils.

Change-Id: I7089b7b2120d5996b4e931c6d971677b663cd43d
Merge "Refactor of sqlalchemy objects unit tests"