CWLProv converter: param info from workflow file

[simleo]

Adds workflow / tool parameter information from packed.cwl to the crate. In particular:

• More accurate type information (e.g., whether it's Any or multi-type, which cannot be inferred from the retrospective provenance)
• Info on defaultValue, encodingFormat, valueRequired (see FormalParameter)
• Info on parameter connections. I could not find any guidance on this on Bioschemas, so I overloaded connectedTo. We can change this later if we find something more appropriate. Other properties I've considered: affectedBy, causeOf, equal, isBasedOn, isRelatedTo / isSimilarTo, relatedTo, sourcedFrom

Also adds a Markdown doc on mapping CWL types to RO-Crate types, with examples.