JSON Schema - include latest spec updates around CredSchema/digestSRI

[decentralgabe]

• Add enforcement of credential schema for json schema credentials and associated tests

[codecov-commenter]

Codecov Report

Merging #455 (0b9d50b) into main (c5f453c) will increase coverage by 0.07%.
The diff coverage is 75.00%.

❗ Current head 0b9d50b differs from pull request most recent head 56929a7. Consider uploading reports for the commit 56929a7 to get more accurate results

@@            Coverage Diff             @@
##             main     #455      +/-   ##
==========================================
+ Coverage   57.35%   57.42%   +0.07%     
==========================================
  Files          67       67              
  Lines        7479     7499      +20     
==========================================
+ Hits         4289     4306      +17     
- Misses       2454     2455       +1     
- Partials      736      738       +2     

Files Changed	Coverage Δ
credential/model.go	39.13% <ø> (ø)
credential/schema/model.go	65.57% <ø> (ø)
credential/schema/vcjsonschema.go	60.75% <75.00%> (+5.58%)	⬆️

[andresuribe87]

We will also need to validate that a VC that's setting the credentialSchema.digestSRI property, has a value which matches against the locally calculated digestSRI. This typically involves dereferencing credentialSchema.id, and then following the spec of SubResource Integrity.

I would prefer that we do that in this PR, so that the same mechanism is used for every VC (instead of special casing VCs who's type property is JsonSchemaCredential). That said, I'd understand leaving that for another PR. Up to you.

[decentralgabe]

I'd rather take that in a separate PR, but opened an issue #456