Implement a new test case for volume cloning functionality

A test is added for the volume cloning functionality (we didn't
have any). Also fixes an issue in base class where we want the
volume IDs to be added as soon as possible into the creation list,
to make sure the cleanup deletes volumes in error state too.

Change-Id: I624ddbf80a2000987c58ea3baa8db96ab9cfde6f
Fixes: bug #1191804
Merge "Implement a new test case for volume cloning functionality"