jsonptr / json-patch dependency conflicts

[clux]

tracking issue for jsonpatch feature dependencies and compile issues when using latest versions of all these

we depend on:

• jsonptr @ 0.4.7 - not latest - they have made breaking changes (see failures in Update jsonptr requirement from 0.4.7 to 0.5.1 #1537) without much in the changelog)
• jsonpatch @ 2.0.0 (currently latest)

Problem: jsonpatch @ 2.0.0 depends on jsonptr 0.4.7. We cannot bump jsonptr until jsonpatch bumps its pin of jsonptr.

In particular, the operations depend on Pointer which has changed.

If you see compile errors when using latest, this is expected. Pin jsonptr to 0.4.7 for now.