Translatable::populateSiteConfigDefaults
When the SiteConfig object is automatically instantiated, we should ensure that 1. All SiteConfig objects belong to the same group 2. Defaults are correctly initiated from the base object 3. The creation mechanism uses the createTranslation function in order to be consistent This function ensures that any already created "vanilla" SiteConfig object is populated correctly with translated values.
This function DOES populate the ID field with the newly created object ID
Signature
protected function populateSiteConfigDefaults()