Corpus form: support URL fields #1859
Description
Currently, the corpus form does not support entering URL fields, because it was not a must-have, but adding support for this is a small addition. Required additions:
- Detect URL columns in the CSV field import
- Enable the URL type as an option in the frontend form. (The backend already supports this.) URL fields do not support searching, filtering, sorting, or visualisations, so these questions should all be hidden/disabled for URL fields.