configurator: use business template for categories
Make erp5_configurator_standard use erp5_configurator_standard_categories.
Since this is the business templates for standard (SME) configurator categories, it seems logical to install this business template when installing SME configuration.
Before these changes, standard configurator was using a spreadsheet ( standard_category.ods ) to define the categories. Now this spreadsheet is almost empty, it only contain group and site that are custom and the configurated instance will install erp5_configurator_standard_categories business template.
The main goal was to make generated configuration use unit conversion module instead
of the obsolete quantity properties on quantity unit categories, but I thought it would make sense to use this erp5_configurator_standard_categories business template that is otherwise not used.