RunSSZStaticTests executes "ssz_static" tests for the given fork of phase using the provided unmarshaller to hydrate serialized test data into go struct pointers and also applies any custom HTR methods via the customHTR callback.

SSZRoots is the format used to read spectest test data.

CustomHTRAdder adds any custom HTR methods for the given object.

HTR is the HashTreeRoot function signature.

Unmarshaller determines the correct type per ObjectName and then hydrates the object from the serializedBytes.