Add tags to operation label relations

Ok, I end up here after tracing why we are getting a watchdog message about tags: Serious problem in tag parsing, please check that you're using a supported version of git!.

So, while fixing it I just notice that the relations between tags and operations are not store in the same way branches and operations are stored now fine.

I am marking this as critical because we would need a re-parse to actually have it working.