fix(server): Remove attached subscriptions when session is deleted
fix(server): Remove attached subscriptions when session is deleted

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