Function registers_credits 

pub fn registers_credits(
    uh_course_code: Option<&str>,
    completions_can_be_registered_to_sisu: bool,
) -> bool

Whether a module’s completions are registered at all: it needs a course code and completions_can_be_registered_to_sisu on. Mirrors the SQL side’s TRIM(cm.uh_course_code) <> '' AND cm.completions_can_be_registered_to_sisu predicates.