feat(server): Add user token signature check for x509 identity token
feat(server): Add user token signature check for x509 identity token

JGrothoff/open62541,open62541/open62541,jpfr/open62541,StalderT/open62541,open62541/open62541,jpfr/open62541,JGrothoff/open62541,open62541/open62541,StalderT/open62541,StalderT/open62541,open62541/open62541,JGrothoff/open62541,jpfr/open62541,JGrothoff/open62541,StalderT/open62541,jpfr/open62541