This reverts commit 1f935d5f.

- Individual grouping based on GroupBy content (defined in config)
- Allow grouping by multiple columns
- Handling NaN while creating individual groups
- Handling '+' separrated group names

(Adding missing columns)

... to reflect latest changes in ews-advisory-builder.

...to reflect latest changes in underlying package ews-advisory-builder.

Requires the file of manual-surveys-to-add to have a consistent country column name and entries.

This is moves field area calculations out of the source_gen package and into the server-specific load function.

# Conflicts:
#	configs/docker/build/Dockerfile