message: fix: rename datasource->dataset in error message
diff: @@ -126,7 +126,7 @@ class QueryContextProcessor:
  if invalid_columns:
  raise QueryObjectValidationError(
  _(
  - "Columns missing in datasource: %(invalid_columns)s",
  + "Columns missing in dataset: %(invalid_columns)s",
  invalid_columns=invalid_columns,
  )
  )
  