EquivalentPolicies checks whether the given policy sets are equivalent, as in,
they contain the same values. The benefit of this method is that it leaves
the "default" policy out of its comparisons as it may be added later by core
after a set of policies has been saved by a backend.
ParsePolicies parses a comma-delimited list of policies.
The resulting collection will have no duplicate elements.
If 'root' policy was present in the list of policies, then
all other policies will be ignored, the result will contain
just the 'root'. In cases where 'root' is not present, if
'default' policy is not already present, it will be added.
SanitizePolicies performs the common input validation tasks
which are performed on the list of policies across Vault.
The resulting collection will have no duplicate elements.
If 'root' policy was present in the list of policies, then
all other policies will be ignored, the result will contain
just the 'root'. In cases where 'root' is not present, if
'default' policy is not already present, it will be added
if addDefault is set to true.