Test topology handling more

[sajith]

When testing SDX Controller, a new issue surfaced that was not caught in unit tests. I have not managed to capture all the details. This issue is a reminder to myself to investigate this later.

When SDX Controller starts up, it attempts to restore at least some of its previous state by loading the combined topology from the database. When we add further topologies to this, and then try to place a connection request, PCE fails to find a path.

It was the original static topologies that were re-added, and it was the sample static connection request that we tried again. It sounds like we could add a new test: keep adding the same topologies over and over again, and make sure that nothing breaks.