pass frozen DAOD test when non-interested branches added/removed

For the frozen derivation test, in the case of removing/adding the branches that are not on the branches of interest list, we do not want to trigger the CI test to fail.
This MR added a mutual exclusion option in the diff_root. And by adding --inexact-branches option, it allows us to change the message from error to info level in the above mentioned cases.

cc @dguest