Add file upload route for devices

[matt8100]

• Reorganize routes and triggers with new structure
  • I'm thinking each route/trigger should have its own dedicated file within the structure for modularity

src/ --device/ ----routes/ ----triggers/ --webapp/ ----routes/ ----triggers/

• Add a route for file upload
  • Takes in a JSON body containing the device name, file name, and file buffer
  • Stores files within a bucket named after the user UID, in a folder named after the device
  • Perhaps will need to add parameters to further control where files are stored? I.e. timelapse pics versus some other file?

Closes #5