Recipe to mask of variables to urban areas

### What problem does your feature request solve?

Some variables would be useful to mask to urban areas (e.g. incoming shortwave radiation, temperature) for energy purposes.

### Describe the solution you'd like

A simple recipe is all that is required. Dependent upon #2032.

### Describe alternatives you've considered

Start by reading issue #2032 and locating the repository’s existing recipe patterns. Identify how recipes select variables and apply geographic masks, then confirm that the new recipe can mask energy-related variables such as incoming shortwave radiation and temperature to urban areas.

Written by the indexing model from the issue text.