Refactor article image upload

Lars Willighagenrequested to merge
phoenix/feature/article-image-upload into phoenix/develop

Testing: (With this merge request the site...)

  • Should allow upload of images and a PDF for articles (where applicable)
  • Should display uploaded images in the HTML after submitting the article
  • Should keep images and PDF after editing existing article
  • Should display a single-article view page for CDLP articles
  • Should open a PDF when clicking on the "Download PDF" button
  • Should display a sensible error when attempting to create an article with an existing type/year/number combination

Merge request reports