Drydock resources and leases currently have "attributes", but these are totally freeform.

One immediate limitation of this is that rendering them is complete garbage, since we just dump the PHID out instead of rendering a handle. D13689 has one approach to this, although it's a little bit hard-codey.

In the longer run, we should formalize which attributes are available and their types, so rendering code can do something reasonable and stuff like setAttribute(...) can be validated, and the meaningful attributes can be listed to make resources and leases easier to work with.