fix(manager upgrade): encapsulated details check in a subTests
fix(manager upgrade): encapsulated details check in a subTests

Since failure of the tasks' detail comparison shouldn't pervert the rest of the test
from running, I encapsulated each inside a subTest context manager.

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests