message: Implement error handling in maybe_read_region calls
diff: @@ -130,8 +130,14 @@ mod iter_support {
  end_ptr: u32,
  order: i32,
  ) -> i32 {
  - let start = maybe_read_region(ctx, start_ptr, MAX_LENGTH_DB_KEY);
  - let end = maybe_read_region(ctx, end_ptr, MAX_LENGTH_DB_KEY);
  + let start = match maybe_read_region(ctx, start_ptr, MAX_LENGTH_DB_KEY) {
  + Ok(data) => data,
  + Err(_) => return ERROR_READ_FROM_REGION_UNKNONW,
  + };
  + let end = match maybe_read_region(ctx, end_ptr, MAX_LENGTH_DB_KEY) {
  + Ok(data) => data,
  + Err(_) => return ERROR_READ_FROM_REGION_UNKNONW,
  + };
  let order: Order = match order.try_into() {
  Ok(o) => o,
  Err(_) => return ERROR_SCAN_INVALID_ORDER,
  