adjust did document schema validation

[Phil91]

Current Behavior

When trying to validate a valid did document with

"@context": [
   "https://www.w3.org/ns/did/v1",
   "https://w3id.org/security/suites/ed25519-2020/v1"
],

the validation fails because only

"@context": [
   "https://www.w3.org/ns/did/v1"
],

is allowed

Expected Behavior

A did document with the two context entries should be validated as valid.

Steps To Reproduce

Create a wallet with the new DIV Provisioning Api, the did document contains the @context with two entries and is marked as invalid.

Additional Information

The context with two entries is valid due to the catena-x standard