Feature summary:
New API route to retrieve an array of statements which have been rejected by the currently logged in user.

Method: GET only
Suggested url: api/get-rejected-statements
Request data: file
Returns: JSON (array of depict items)

When making the API call, you only need to provide the file because the user_id will come from the currently logged in user.
The back end should then query the Suggestions table for all rows with matching file and user_id.
We only need to return the depict_item from the database. So example results would look like this if the user had rejected 3 different suggestions on the file specified:

["Q123", "Q345", "Q678]

Use case(s):
The front end needs to check which suggestions have been rejected by the logged in user, so they can be filtered out of the list displayed.