feat(pubsub): The publish callback takes the server mutex
feat(pubsub): The publish callback takes the server mutex

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