Geolocation enhancements

[abettermap]

Related

Wishlist extension of #105.

Summary

Snackbar confirmation/success alert

e.g. "Now using your location" or whatever provides feedback that something just happened. Would be temporarily shown (3-5 seconds), and only once per session, when the user first toggles it on.

Dot animated radius

Make its size dynamic based on location accuracy (like Google Maps does or at least used to).

Loading spinner and/or text while we're waiting

...whether for user to click "Allow" or for the actual location acquisition. There was one in the default btn control and it was kinda nice. Not sure where to put this one, though. Obviously in the popout or wherever the switch/btn lives, maybe some text below it saying "Acquiring your location...".

Or, if the snackbar was implemented, could just put the text there and switch it out once the location is ready.

Zoom/pan consistent w/other controls

Should be same animation/transition that we use on any of the other zoom controls, and use the same logic of "only zoom in closer if zoom level is further out than 14" in determining whether or not to zoom in more.

Error or warning snackbar for problemos

...whichever makes sense for each of these:

• Couldn't find location
• Accuracy sucks
• Location is outside the map
• User clicked "Block"

"Close" btn

The Geocode/boundaries popover "X" from #78.

Implementation

• Most of the functionality: http://visgl.github.io/react-map-gl/docs/api-reference/geolocate-control#properties
• Shnackers: https://material-ui.com/components/alert/