fix(shuttles): Fix indexes changing to 0-based and displayed stop names changing when stops are reordered

[rudiejd]

Summary of changes

Asana Ticket: [extra] 🏹🐛 Map view - stops index changing (from first stop as 0 or as 1

Problem:
When re-ordering shuttle stops for a new shuttle, the indexing of stops would change from 1-based to 0-based after the first reordering.

Solution:
Start using 1-based indexing for stops in the stop_input component.

Problem:
When re-ordering shuttle stops for a new shuttle, stops with auto-completed names would switch from the auto completed value (e.g. 1 - Washington St opp Ruggles St) to just the value of the stop ID e.g. just 1

Solution:
On every re-render of stops, ensure that the value of the stop_input component is the human readable value. I fetch from the stop from the changeset if it's already there, otherwise I fetch the stop from the DB.

Reviewer Checklist

• Meets ticket's acceptance criteria
• Any new or changed functions have typespecs
• Tests were added for any new functionality (don't just rely on Codecov)
• This branch was deployed to the staging environment and is currently running with no unexpected increase in warnings, and no errors or crashes.

[meagharty]

not blocking: I'd love to have :display_stop / stop_or_gtfs_stop_for_stop_id consolidated in some way but I think this function hints at the (existing) issue where we were deal with the changes and the committed values across new and edit.

[rudiejd]

I agree - I feel like display_stop is probably unnecessary since the stop is probably loaded in the changeset by the time the user has entered it. In the interest of keeping this PR small and making iterative improvements, I'm going to hold off on that for now.

[meagharty]

thanks for fixing up both of these bugs!