Add support for street-level imagery

[upintheairsheep]

Hello, I would like to have a way to move Mapilary content to Google Street View and vice versa, with KartaView being another option to transfer to/from. Mapilary is basically the FOSS alternative to GSV, with KartaView being another alternative. The service should support moving photospheres to Mapilary, photo paths to Mapilary, and 360 videos to Mapilary, and for Mapilary, there should be the ability to do the opposite for their photo paths. Photo paths are no longer possible to create on Google SV now, but the API can be changed to allow this to happen.