Monorail's FLT page currently uses vaadin-upload, which is useful but probably not quite how we want our upload components to look/work long-term. 

We should make our own component that does something similar so we can:
- customize the look/feel to fit our design goals
- customize the API more to fit with how our services  
- avoid having to depend on vaadin's various dependencies. 
- allow the possibility for future UX streamlining/integration. ie: Dragging and dropping an image into a text edit field uploads it.