Add problem package and statement to problems endpoint

[niemela]

Add the problem package and statement to the problems endpoint.

Also, merge the file reference types (IMAGE, VIDEO, ARCHIVE, STREAM) into a single file reference type (FILE). Note that FILE was already used, but not defined.

[niemela]

I am concerned with the new requirement for videos (team and reactions) & streams to have a width and height.

I would argue that this is not new. The old text said: Width of the image, video or stream in pixels. Should not be used for ARCHIVE.

We haven't done this before, and the latter requires us to either hardcode it or connect to every stream - would like to discuss on the next call.

I would have no trouble changing to: Width of the image. Required for files with mime type image/*. (and same for height). I only added the rest to not make a change.

[deboer-tim]

I would have no trouble changing to: Width of the image. Required for files with mime type image/*. (and same for height). I only added the rest to not make a change.

Before it was "Nullable: no for IMAGE", now it's "Nullable: depends" and "Required for files with mime type image/ and video/ " , which sounded like a change to me. I'd be good if we remove the "and video/*" as you suggested, or we can discuss.

[niemela]

I'd be good if we remove the "and video/*" as you suggested

Done.