Add inline images to Delegate Reports

[gregorbg]

Adds the ability to directly force image uploads in a Delegate Report, instead of "butchering" it through Markdown.
Advantage 1: We can verify that a Delegate indeed uploaded images before submitting the report.
Advantage 2: We can query these images later, aggregate them, move them elsewhere without much hassle, etc.

[gregorbg]

Pictures!

How it looks in the "Edit" interface on the website:

How it looks in the rendered report (pictures are small on purpose, clicking them will open a new tab with the full-size version)