[#39] Add completion status to drawings

[krissy]

Addresses #39

What this does

Adds mandatory completion statuses (currently pending and completed) to drawings, to cater for cases field workers may need to split up image uploading and data entry. Need to improve UI for this later.

Also fixes some small bugs and linting bits.

Screenshots

[steverabino]

:+1: One question, but if that's good 🚿