Reduce the use of generic container APIs

Introduction

In preparation for porting Files to GTK4, we are following the GTK3 to GTK4 migration guide, by breaking it into smaller independent tasks which anyone can pick up.

This issue is about one steps of this guide:

Reduce the use of generic container APIs

GTK 4 removes gtk_container_add() and gtk_container_remove(). While there is not always a replacement for gtk_container_remove() in GTK 3, you can replace many uses of gtk_container_add() with equivalent container-specific APIs such as gtk_box_pack_start() or gtk_grid_attach(), and thereby reduce the amount of work you have to do at the time of the switch.

Tasks breakup

• src/nautilus-batch-rename-dialog.c ─ !704 (merged)
• src/nautilus-column-chooser.c ─ !703 (merged)
• src/nautilus-file-conflict-dialog.c ─ !724 (merged)
• src/nautilus-file-operations.c, src/nautilus-files-view.c, src/nautilus-floating-bar.c, src/nautilus-notebook.c, src/nautilus-places-view.c, src/nautilus-query-editor.c, src/nautilus-search-popover.c, src/nautilus-special-location-bar.c, src/nautilus-toolbar.c, src/nautilus-trash-bar.c, src/nautilus-window-slot.c, src/nautilus-x-content-bar.c ─ !728 (merged)
• src/nautilus-view-icon-item-ui.c ─ !717 (merged)