Default routes provided by the generator don't include everything

[tiberiuichim]

https://github.com/plone/volto/blob/05162223a7c08000f3cf86b8ebdd784cbef04fe7/packages/generator-volto/generators/app/templates/src/routes.js#L7

As you see, in the routes.js the generator uses the default_routes. But the multilanguage routes are not included in the default routes, which is a problem.

All these:

https://github.com/plone/volto/blob/05162223a7c08000f3cf86b8ebdd784cbef04fe7/src/routes.js#L272

and https://github.com/plone/volto/blob/05162223a7c08000f3cf86b8ebdd784cbef04fe7/src/routes.js#L266-L269

should be moved in the default routes.

[tiberiuichim]

CC @erral