Add Visit UX improvements

## Basic Information
Volunteers are only ever going to approximate, and _some_ info is better than none.
So feature suggestions:
- Distance fields non-mandatory, granularity via numeric picker can be 500m. Check null values still catered for by reports okay?
- "Commute Method" non-mandatory, should include "Walk" as an option.
- "Start Time" can be renamed "When", granularity 15 minutes. Default to the start of the current hour.
- "Duration" will usually be 15 or 30 minutes. For less clicks/typing, suggest change to dropdown:
- 0:15
- 0:30
- 0:45
- 1:00
- ...
- 3:00
- "Submit" button is very dev-centric language. Suggest change to "Save".
- After submit, the visit list should auto-expand the visit that has just been added. This helps the user confirm they've entered details correctly, and prompts them that they can report an associated incident or pet concern.