Renderer rollback does not work

When a service creation fails, all OLM and renderer operations are supposed to be rolled back. There are at least a couple of problems with how this is currently implemented:

1. OCh interfaces are deleted in the same order as they were created. MC is deleted before NMC, which fails because the NMC includes a reference to the MC as supporting interface.
2. NMC is deleted before the roadm connection in opposite direction is deleted, which fails because the roadm connection includes a reference to the NMC.

These things are properly handled for a normal service deletion but rollback does not work.