Add API endpoint to determine most likely location of client

[DatanoiseTV]

Even though we can currently determine the last known location of a client by sending a request to GET /api/v1/location/FAMILY/DEVICE, it would be useful to have a simplified API endpoint e.g. GET /api/v1/location_min/FAMILY/DEVICE which just returns the name and probability of the most probable last location. This would save a lot of memory on embedded devices by avoiding unnecessary JSON parsing.

[schollz]

Yeah, I agree that's a useful endpoint. I will add that.

[DatanoiseTV]

@schollz Another useful response in the endpoint would be the time in seconds when the client was last seen at that location.

[schollz]

Ok @DatanoiseTV, added in f2e6c94!

Try it here: https://cloud.internalpositioning.com/api/v1/location_basic/testdb/zack2@gmail.com

Let me know if that works!

I think it won't work on ESPs (I think), but FIND also supports some MQTT endpoints for more efficient transfers (just fyi!)

[DatanoiseTV]

It works just as intended.