refresh with latest schema-salad, proposed CWL v1.2.1 changes

- `Savable` → `Saveable` typo fix changes some class names
- `default` field type is now explicitly including `File` and `Directory` alongside `Any`
- `hints` is now defined as any of the known requirements, or `Any` (should be a nice simplification)
- the refscope for workflow `outputSource` was corrected from 0 to 1

Author: mr-c