fix: failure to verify jsonld on non-conformant doc but vaild vmethod

[dbluhm]

Minor fix for jsonld verify route.

[dbluhm]

Tests to hit the error path pending, hoping to get this ready for merge ASAP

[codecov-commenter]

Codecov Report

Merging #1301 (2887a53) into main (1f8eeb0) will decrease coverage by 0.00%.
The diff coverage is 94.11%.

@@            Coverage Diff             @@
##             main    #1301      +/-   ##
==========================================
- Coverage   95.43%   95.42%   -0.01%     
==========================================
  Files         476      476              
  Lines       28977    28980       +3     
==========================================
+ Hits        27653    27655       +2     
- Misses       1324     1325       +1     

[andrewwhitehead]

What is it if not a VerificationMethod?

[dbluhm]

The dereference method can also be used to dereference a Service. The method itself has a return value of Resource which is the base VerificationMethod and Service build from. It's a little on the complicated side due to attempts to work with documents that don't strictly conform to the schema outlined in the DID spec. In that case, a plain Resource object is returned since the more feature rich parsing failed. We give that parsing another try for just the identified resource here.

Alternatively, I could see this being simpler: we default to dereferencing resources from a DID document as if the doc itself was non-conforming but modify the dereference method to also take a parameter asserting that the dereferenced resource is a VerificationMethod or Service and "casts" the resource to one of these objects (or whatever type that was passed in) or fails.