Store map state in URL for better UX

[vitale232]

If the user leaves the page then comes back, the whole app reloads. This is not desirable behavior.

We should use query params in the URL to manage the map state. Something similar to Google Maps urls:
ipa.timelinetamer.com/@43.5,-72.1,12z
ipa.timelinetamer.com/@lat,lon,zoom

[vitale232]

This was implemented using classic query parameters. URLs now accept an argument for latitude (lat), longitude (lon), and zoom level (z).

Here's an example URL:
https://ipa.timelinetamer.com/?lat=42.7135&lon=-73.8162&z=17