number of user provided data overlays is not increasing correctly

overlays added/removed in the left panel are numbered "randomly", i expected numbers increase/decrease. Also, overlays added in admin panel for that project are numbered not correctly in the left panel.

The problem is not with adding, but with removing.

Adding assumes that the order is correct (which is not true after remove)

changed milestone to %v14.0.0~beta.0

added BUG label

created merge request !907 (merged) to address this issue

mentioned in merge request !907 (merged)

closed via merge request !907 (merged)

mentioned in commit df8cc024