Do not always include real filename or URL in imagery_used

[poevak]

Pull request #4440, initiated by issue #4385, changed so that the real filenames of local GPX files were made public.

I think this is pretty terrible from a privacy point of view. It's not at all evident in the editor that the filename will be made public: the only way to see that it will is to expand all the tags and then hover over the sources field (the field is only wide enough to show the satellite imagery reference).

In essence, the user is tricked into submitting more information than he or she might have intended to. If we accept that, why stop at sneaky submission of just metadata when we could simply upload and make the entire trace public?

As the editor does not allow the user to edit the filename about to be submitted, despite the fact that the user could have set any filename before doing any edits, it is necessary to redo the edits should a sensitive filename have been accidentally set.

I love the simplicity of the iD editor, so adding options or extra editing fields doesn't seem like the best idea to me. Is there really any real value of including local filenames or unrecognized URLs?

[bhousel]

I admit that I did not think that anyone would have an issue with the privacy of their gpx filenames. I guess we don't really need to put an actual filename there. Sorry!

[JamesKingdom]

Maybe we could include the URL if it is on OpenStreetMap, but just say "Local GPX" if it's uploaded?

[bhousel]

I changed the code to generate a string like '.gpx data file' or '.geojson data file' depending on the extension:

[jidanni]

Allow us to recall that there are four levels of
https://wiki.openstreetmap.org/wiki/Visibility_of_GPS_traces .
So some consideration of at least the people choosing Identifiable should be made...