Implement geo params for v1 API

[Skud]

Implement geolocation parameters for the v1 API, so that you can query for eg. "plantings near Ballarat" or "crops planted near New York".

Other user requests: I would love to be able to send an API request like

/api/v1/crops/{lat: X, lon: Y} /api/v1/seeds/{lat: X, lon: Y}

And return the crops/seeds being grown close to that specific location. I'm new to API development, so I'd be glad to contribute on something like this as well, and learn along the way.

Enabling changes

#2375

Other considerations

Having this clearly demonstrated in the API documentation would be useful.