Function restore_create_database_creator 

fn restore_create_database_creator(
    metadata: &MetadataMap,
    role: i32,
    task: &mut DdlTask,
    query_context: &mut QueryContext,
) -> Result<(), Status>

Restores the authenticated creator omitted from the protobuf create-database task.

The frontend sends the serialized [CreatorGrantIntent] in both a reserved query-context extension and internal gRPC metadata. This function removes the extension, requires both copies to match on a frontend create-database request, and writes the decoded intent into the task. Missing both preserves legacy and admin behavior; missing or mismatched copies fail closed.