[REF][PHP8.1] Fix a couple of deprecations in php8.1 by specifying that return type...

[REF][PHP8.1] Fix a couple of deprecations in php8.1 by specifying that return type may change in BaseParamQuery and by ensuring that we don't pass null into function_exists in I18n class

Replace some ReturnTypeWillChange with later return types as they should be backward compatible

Dave D Fix

Completely switch to just not empty on the customTranslationFunction check