Switch to api.openstreetmap.org API host

[danieldegroot2]

Use api.openstreetmap.org/api/ -and HTTPS- instead of www.openstreetmap.org/api/*.

(Is: openstreetmap/operations#951)

Except for regular link in README.md and index.html.

PR will initially be marked as a draft, as there seem to be unresolved issues upstream.

cc: @bhousel

[bhousel]

Looking into this today..
Weirdly it seems like the /oauth2 related endpoints are the only thing that doesn't work when using api.openstreetmap.org.

When I try it, I get a "301 Moved Permanently" redirect, which triggers a CORS error.

There is some discussion on openstreetmap/operations#951 about it.

[danieldegroot2]

Yes, this is the reason I personally made this a draft as mentioned above.

[bhousel]

I ended up just copying what @tyrasd did in openstreetmap/iD@c4d1390 by making separate url and apiUrl properties. This way it remains backward compatible (url still performs the handshake).

[tsmock]

Since this PR is being linked from all over the place, I'll copy what I said in westnordost/osmapi#33 (comment) .

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Realistically the RFC 8414 compliant endpoints should be used. Those would be https://www.openstreetmap.org/.well-known/oauth-authorization-server and https://api.openstreetmap.org/.well-known/oauth-authorization-server (which redirects to www). The JOSM code does look for that on non-OSM endpoints, but that will probably change so that we don't have URL endpoints hardcoded into the application [for OSM].