Catch NoResultFound in _get_policy_profile_by_name

Add try-except in _get_policy_profile_by_name to raise
proper PolicyProfileNameNotFound if profile not found in
database.

Also unittest is added.

Closes-bug: #1393399

Change-Id: I3ab50a6870ff77a95e0977c75255e9cbd7286fbb
Merge "Catch NoResultFound in _get_policy_profile_by_name"