Change E_CONFIG_SECTION_TABLE to E_CONFIG_SECTION_GRID as it now expects a GtkGrid. Also do the same for E_CONFIG_ITEM_TABLE. Closes: https://gitlab.gnome.org/GNOME/evolution/-/merge_requests/163
Closes https://gitlab.gnome.org/GNOME/evolution/-/merge_requests/124
Closes https://gitlab.gnome.org/GNOME/evolution/-/merge_requests/93
Closes https://gitlab.gnome.org/GNOME/evolution/-/merge_requests/66
Let's have it as it's common to be, which means top level src/ for sources, single data/ for data, and so on.