[Feature] Alternate CWL package representations

[fmigneault]

Description

Using the output of the graph parser/viewer, eg:
https://view.commonwl.org/workflows/github.com/common-workflow-language/workflows/blob/master/workflows/compile/compile1.cwl%23main

It is possible to obtain an interactive view of a given Application Package.
Also, many more formats become available:

Using https://github.com/common-workflow-language/cwltool and corresponding utilities hosted by https://github.com/common-workflow-language/cwlviewer, an Accept header (or f query) could be used to request all these type variations on /processes/{processID}/package.

Furthermore, given HTML support of the API (#636), the CWL could be immediately rendered inline in the process description page (and maybe even more shortcuts/buttons to obtain the alternate formats).

References

• Relates to [Feature] Graph image rendering of contained CWL #213
• Relates to Conformance definitions for /processes/{process_id}/package endpoint #620
• Relates to HTML responses #636