This PR adds indigenous lands to the `boundary` layer by adding new area features for these objects, along with generalization up to z4. It borrows heavily from the technical processing chain of the `park` layer.
I added new `class`, `name`, and `name:xx` attributes to the boundary layer, in order to support the new area features. Should we (or someone extending this schema) come up with new objects to place in the boundary layer in the future, `class` would support additional categories.
Brian Sperlongano