Make dispatch labelling mirror officer labelling.

Dispatch labels are currently built as features. They should be split out into their own code.

In parallel, officer labels should be written as label classes just like officer features.

Start by locating the code where dispatch labels are currently built as features and where officer features are defined. Separate dispatch labelling into its own code and make officer labels use label classes like officer features; inspect existing tests or usage sites to confirm both paths still work.

Written by the indexing model from the issue text.