write_dwca.py to convert camtrap-dp to event core

[peggynewman]

write_dwca.r in the camtrap-dp R package at https://inbo.github.io/camtrapdp/ converts the frictionless data package into an occurrence core.
Create a similar script (or package) that converts the package into an event core dataset for the Wildobs dataset. The event heirarchy will be Dataset-Survey-Deployment, and includes an occurrence extension and multimedia extension (off the occurrence as per the ALA extended data model).

Must be repeatable, there will be more like this.

The images in the dataset exist but we need to be given access - to do once we've got the event structure right.