UserManager as role coordinator

UserManager as role coordinator

- UM to expose API to check if a role name is already in use
- Included search in local authorization configurations when querying for roles on user, getUserRoles()
- Added local authorization code to Junit to exercise the above
- Minor code refactoring to resuse getUserRoles() to avoid code duplication
- Downgrade and changed log level on cache allocation when cache is already present
- Removed new line in UM log messages to be in line with other bundles

Signed-off-by: Alessandro Boch <aboch@cisco.com>