Add "global_south_editor_fractions" to geowiki

format_grant_qr.py of the dashboard repository used to compute
global_south_editor_fractions. However, those computations relied on
global_south.csv, which has been factored out to geowiki. In order to
allow easy updating of global_south_editor_fractions every time
global_south.csv gets updated, we bring it oven to geowiki.

To allow tracing which part went where, we bring the code over
unmodified, and leave adaptions to follow-up commits.

Change-Id: I1cce360170380f4106ef2f43b606950fbf60049b
Use basedir's "global_south.csv" to compute editor fractions

Change-Id: I22e52d0fc7ea79a0042cc8ed58d80604f40b9a31
Merge "Add "global_south_editor_fractions" to geowiki"
Merge "Use basedir's "global_south.csv" to compute editor fractions"