search-locations-dialog: Add ellipsis to the "Add Location" button
requested to merge automerisnaranja/gnome-control-center:ellipsis-add-location-search-locations into main
"Use an ellipsis (…) at the end of a label if further input or confirmation is required from the user before the action can be carried out"
https://developer.gnome.org/hig/guidelines/writing-style.html