[IMP] web: show technical field name in export wizard by hover in debug mode

In export wizard on mouse hover display technical name of field in debug mode

addons/web/static/src/js/widgets/data_export.js

@@ -369,11 +369,11 @@ var DataExport = Dialog.extend({
                 .find('.o_expand_parent')
                 .toggleClass('fa-plus fa-minus')
                 .next()
-                .after(QWeb.render('Export.TreeItems', {'fields': records}));
+                .after(QWeb.render('Export.TreeItems', {'fields': records, 'debug': this.session.debug}));
         } else {
             this.$('.o_left_field_panel').empty().append(
                 $("<div/>").addClass('o_field_tree_structure')
-                           .append(QWeb.render('Export.TreeItems', {'fields': records}))
+                           .append(QWeb.render('Export.TreeItems', {'fields': records, 'debug': this.session.debug}))
             );
         }
 

addons/web/static/src/xml/base.xml

@@ -1134,7 +1134,7 @@
     tabindex="-1"> <!-- tabindex make the div focusable -->
     <span t-if="field.children &amp;&amp; (field.id).split('/').length != 3"
           class="o_expand_parent fa fa-plus"/>
-    <span class="o_tree_column"><t t-esc="field.string"/></span>
+    <span class="o_tree_column" t-att-title="debug and field.id or None"><t t-esc="field.string"/></span>
 </div>
 <t t-name="Export.SaveList">
     <label>Save as:</label> <input type="text"/><button type="button" class="btn btn-sm btn-default">Ok</button>