Make Nominatim-UI run against Photon?

[lonvia]

It would be mighty awesome to have something like nominatim-ui for Photon as well. What are the chances, we can make it work for both APIs?

Without having tried it, the following should do:

• switch search and reverse requests to geocodejson format, so responses are formatted the same
• have configurable API templates
• have configurable extra arguments
• disable details for Photon

[mtmail]

The test suite would depend on two external services, while most users only run one or the other. Maybe forking is easier and later see how much can be shared.