search-button: Port results to GtkListView

Port the search results list to GtkListview. Use bindings to set
the title, icon, and subtitle of each row. Remove GcalSearchHitRow
as it's unused now.

src/gui/gui.gresource.xml

@@ -7,7 +7,6 @@
     <file compressed="true">gcal-meeting-row.ui</file>
     <file compressed="true">gcal-quick-add-popover.ui</file>
     <file compressed="true">gcal-search-button.ui</file>
-    <file compressed="true">gcal-search-hit-row.ui</file>
     <file compressed="true">gcal-toolbar-end.ui</file>
     <file compressed="true">gcal-weather-settings.ui</file>
     <file compressed="true">gcal-window.ui</file>