gtkplacesview: Add some missing button tooltips

The remove server button and the server list one had only icons,
so fix it by adding tooltips to them.

gtk/gtkplacesview.c

@@ -590,6 +590,7 @@ populate_servers (GtkPlacesView *view)
       gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
       gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
       gtk_widget_add_css_class (button, "sidebar-button");
+      gtk_widget_set_tooltip_text (button, _("Remove server"));
       gtk_grid_attach (GTK_GRID (grid), button, 1, 0, 1, 2);
 
       gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), grid);

gtk/ui/gtkplacesview.ui

@@ -275,6 +275,7 @@
                 <property name="direction">0</property>
                 <property name="popover">recent_servers_popover</property>
                 <property name="icon-name">pan-down-symbolic</property>
+                <property name="tooltip-text" translatable="yes">Show recent servers</property>
                 <style>
                   <class name="server-list-button"/>
                 </style>