Update guestbook responses to sort by guestbook response fields

[ekraffmiller]

Overview of the Feature Request
In the JSF frontend, the guestbook responses table is sortable by response fields. We need to add a sort parameter to the guestbook responses API to support this.

What kind of user is the feature intended for?
Anyone with access to manage guestbook page

What inspired the request?
SPA development

[stevenwinship]

@ekraffmiller Can the UI sort by multiple fields? I.e. sorted by date and within the date by type or file?

[ekraffmiller]

@stevenwinship , no it only sorts by individual fields