Feature: #99321 - Add presets for site languages

See forge#99321


When adding a new language to a site, an integrator can now choose

a) to create a new language by defining all values themselves b) from a list of default language settings ("presets") c) to use an existing language if it is already used in a different site

Although c) is always recommended when working with multi-site setups, to keep language IDs between sites in sync, b) is now a quick start to setup a new site.


Integrators spend less time adding new site languages.