Add additional unit tests for read/write of attributes
Add additional unit tests for read/write of attributes

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