Disable map view, fix admin add rides flow

[mjaydenkim]

Summary

• Implement flag to enable/disable map view (due to custom locations, admins don't want the map view yet)
• Fix admin change location modal (flow was kinda clumsy before)
• Add custom locations to admin add location modal
  • Note: there isn't any address validation like there is in the student page. This is easy to implement but I was wondering if we should give admins more leverage to input fully custom addresses; worth discussing in reviews though.

Test Plan

Tested app functionality with and without flags and scheduling rides from admin side

[dti-github-bot]

[diff-counting] Significant lines: 244.

[YottaYocta]

Hi Matthew! Thanks for your PR. Requesting a ride from the admin side worked for me. I think we should discuss the possibilities of reworking the UI in the future, especially how custom string rides work address selection in our system, but I feel that that task is out of scope for now.

I ran into some issues on the rider client when trying to click 'details'; do you have any ideas on what to show on the rider side if a custom string address is requested?

[YottaYocta]

Forgot to include this, but in the admin scheduler panel, the locations of custom rides aren't being displayed

[mjaydenkim]

@YottaYocta i think these issues have been fixed, take a look !