When there's no Review UI for a file attachment, the thumbnail view

itself allows adding a comment for a file. This was processing through

the comments data expecting those to be an array, but after the work to

add typing and make all the individual review UIs consistent, the data

here is an object with arrays as the values. This change fixes it to

properly iterate over that.

Was able to add a new comment on a file attachment that did not have a

review UI.