Reconnecting Token Generator for Annotation Tool [Fix]

**Background:** Follows PR #3466 which was reverted and pulled from master because of an error during staging.

**Instructions:** In order to instantiate the tool head over to Advanced Settings for the course and add "textannotation" to the advanced_modules key. Then create a new unit. An "Advanced" large green button should show up that when clicked will allow you to select the "Text Annotation" option. It will show a default testing image. Make sure that the annotation_storage_url and annotation_secret_token are filled in with test values in the course's Advanced Settings.

**CMS Update:** None.

**LMS Update:** The offending line below is number 149. It should never have been in this PR at all, but rather PR #3480. In previous builds you could have ```${diacritic_marks}``` and if the variable didn't exist it would just resolve to empty string. Thus saying ```diacritics: ""``` but now it throws a Name undefied error.