Add Cloudflare Location (CDN origin) context to home page

[brianfeister]

Summary

The goal of this PR is to unlock a "first pass" at location context driven event filtering as a default for our DynamoDB queries.

Video walkthrough of the functionality: https://drive.google.com/file/d/1aB7OzDJ_DChh_ishU6-5TL3UOs_ysh6Y/view?usp=drive_link

Testing this PR

Check the boxes once you've validated the following:

• [x] I see one event at https://testingnear.me/?lat=40.6925&lon=-74.1687 (this is forcing your lat and lon to match the range where we would expect to see the "Chess Tournament" event
• [x] I see zero events at https://testingnear.me/?lat=0&lon=0 ("Null Island") because nothing is happening near in that area
• [x] I see one event if I'm located in the DEN (Denver) general vicinity and zero events if I'm located far enough away at https://testingnear.me