Submissions Page Implementation

[tjuav]

To effectively interact with #148, the Submissions tab needs to be heavily refactored.

• Retrieve the number of images on tj-uav/FlightSoftware (FS) from server/handlers/image.py, and allow users to select images that can be downloaded (using image download routes from Image Handler Refactor #148)
• Refresh the page with new image counts from backend
• Display every downloaded image (and every image with downloaded sections)
• For every image with objects, include CV results (location + classification) for each object
• Include an option to create a drop waypoint at an object (using Drop Waypoints #150)