Add success and error snackbars to the templates list page (#36808)

* Add success and error snackbars to the list page

* Fix Unit Test error

* Apply 'is-navigation-open' to interface skeleton

* Fix NavigationToggle unit test

* Apply suggestions from code review

Co-authored-by: Robert Anderson <robert@noisysocks.com>

* Use deleting

* Remove snackbars for creation

* Add notices for reverting

* Fix test

* Add getLastEntityDeleteError

* Add comment

Co-authored-by: George Mamadashvili <georgemamadashvili@gmail.com>
Co-authored-by: Robert Anderson <robert@noisysocks.com>

packages/edit-site/src/components/list/style.scss

@@ -140,3 +140,9 @@
 	height: $grid-unit-40;
 	border-radius: 100%;
 }
+
+.edit-site-list.is-navigation-open .components-snackbar-list {
+	@include break-medium() {
+		margin-left: $nav-sidebar-width;
+	}
+}