Add "OSM Note" as changeset Source option

[martin-kokos]

OSM Notes are one of the key features and the number of them are growing ( http://resultmaps.neis-one.org/osm-notes ) . Some mappers even specialize on resolving notes. I think it makes sense to have it as one of the presets when saving a changeset.

[tordans]

I expect this to be a feature request in the iD Repo. But a maintainer can move the issue over there.

[martin-kokos]

Actually I found the options are not in iD but here in schemas. See #189

[tyrasd]

this was already fixed in #189