Comment 9 for bug 1706196

One of the most important use cases for tags is acting as constraints for things maas doesn't model. For example, if I have a tag that is generated based on a xpath query to lshw, and I use that tag as a constraint when allocating a node, I want to either get a machine with lshw that matches the query or get an allocation failure - I do not want a VM generated to match the other constraints. The current behavior breaks that use case.