edit → widgets Relation

File in mainwindow/edit	Includes file in widgets
mainwindow_edit_edge.cpp	graphtablewidget.h
mainwindow_edit_filters.cpp	filterbarwidget.h
mainwindow_edit_filters.cpp	graphtablewidget.h
mainwindow_edit_node.cpp	graphtablewidget.h
mainwindow_edit_relation.cpp	graphtablewidget.h
mainwindow_edit_selection.cpp	graphtablewidget.h