Request note modification permission when setting up oauth

[ToeBee]

The new "Notes" feature on osm.org introduced a new oauth permission. JOSM does not request this permission when setting up oauth tokens. According to a quick grep through the rails port, this permission is identified by the string "allow_write_notes" in the authorization process.

I am attaching a patch that should be a good start on adding this but I think something is missing. It didn't seem to work when doing the fully automatic setup although this is hard to verify because osm.org does not let you view the details of existing oauth configurations. When doing semi-automatic, the "Modify notes" permission is not being listed in the web page that JOSM opens up after step 1. The thought occurred to me that this might be a bug in the rails port although I believe another application has successfully used oauth to edit notes so this seems a little unlikely. I'm not familiar enough with oauth to know exactly what is going on here so I'm hoping someone else can take what I have and figure out whatever is missing.

This is blocking further work on the Notes plugin (#8193).

[ToeBee]

Patch to add the new note permission to the oauth setup process