Possibility to switch the query mode for terms widget and menu item

We should provide the ability to switch the default query mode for terms widgets and menu items. The current default is to combine multiple options with "OR", but the user should be able to configure this.

• Add query_mode option to the terms widget setup. This will determine how items added to through the widget will be handled. This can be changed in the widget settings.
• Add query_mode option to the terms menu item setup. This will determine how items added to through the menu item will be handled