Internationalized routing for Base Router

Last week, Symfony published a new component for realizing international routes.
http://symfony.com/blog/new-in-symfony-4-1-internationalized-routing

I would like to see this feature in the Magento Base Router.
This will offer us locale specific routes.

e.g.

• default en_US: /contact
• de_DE / de_AT / de_CH: /kontakt
• it_IT: /contacto

This could be solved by adding new config elements to routes.xml.

My idea is to provide a general replacement for a frontName and explicit mapped rewrites for single actions.

Draft Example:

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
    <router id="standard">
        <route id="catalog" frontName="catalog">
            <module name="Magento_Catalog" />

            <localizedFrontName>
                <prefix frontName="katalog" locale="de_DE" />
            </localizedPrefixes>
        </route>

        <localizedActionPreferences>
            <preference for="catalog/product/view" rewrite="katalog/produkt/anzeigen" locale="de_DE" />
            <preference for="catalog/category/view" rewrite="katalog/produkt/anzeigen" locale="de_DE" />
        </localizedActionPreferences>
    </router>
</config>

Start by reading the Magento Base Router and the routes.xml configuration schema, then compare the proposed locale-specific front names and action rewrites with the Symfony internationalized routing component referenced in the issue. Done should be defined as locale-specific routes for the shown examples, with configuration validation and coverage for the routing behavior.