Feature: #99321 - Add presets for site languages

See forge#99321

Description

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

  1. to create a new language by defining all values themselves

  2. from a list of default language settings ("presets")

  3. 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.

Impact

Integrators spend less time adding new site languages.