Replace /add, /edit, /delete endpoints with POST, UPDATE/PATCH, and DELETE methods

[chambbj]

Rather than having multiple endpoints for aoi and export operations such as add, edit, and delete, use HTTP methods of POST, UPDATE (or PATCH), and DELETE to describe the operations.

• [x] GET /aoi/add becomes POST /aoi
• [x] GET /aoi/edit/:pk becomes UPDATE /aoi/:pk (perhaps PATCH)
• [x] GET /aoi/delete/:pk becomes DELETE /aoi/:pk
• [x] GET /aoi/:pk/generate/pointcloud becomes POST /export (or POST /aoi/:pk/export)
• [x] GET /aoi/:pk/generate/raster becomes POST /export (or POST /aoi/:pk/export)
• [x] GET /export/edit/:pk becomes UPDATE /export/:pk (perhaps PATCH)
• [x] GET /export/delete/:pk becomes DELETE /export/:pk

[AlexMountain]

v3 has been updated with the appropriate GET/POST/PATCH/DELETE http methods for all AOI and export calls.