[Implementation Guide] Moar Test Vectors

[bumblefudge]

• Both positive and negative test vectors, particularly for filters/matching
• Test vectors sourced from real-world implementations, such as (not a binding list, just spitballing!)
  • holder binding / confirmationMethod examples
  • mDLs, OIDC identity assurance tokens, etc
• Examples of the "brutality" of real-world filter properties (see #421 #422 #423)

[bumblefudge]

Would it make sense to add an example of the "all credentials of type foo" filter described by niels in #406 ? it could be a good test vector, and it could also be linked to from an explanation in impl guide about trust establishment/overasking/etc... spec contributors vote with emojis when you see this hehe

[bumblefudge]

Merged with #416