Move over a reflection module that taskflow uses

Taskflow has a quite useful reflection module that it would
appear others would benefit from having access to, so instead
of keeping it in taskflow, move it over to oslo.utils so that
others can benefit from it.

Potential users:

- Oslo.db
- Cinder
- Taskflow (where the code used to exist)
- Others doing name lookup or other reflection functionality

Change-Id: I9fbdd86966afddb862cb7faed2f88298a9f956cf
Merge "Move over a reflection module that taskflow uses"