refactor: change GetGuardMembers return type,

to IEnumerable<MemberInfo>.
refactor: change GetInitializedMembers return type,

to IEnumerable<MemberInfo> instead of MemberCollection<T>.
refactor: not use MemberInfoCollection<T>

in PublicMethodDataAttribute.
refactor: use Experiment.AutoFixture instead of AutoFixture.Contrib.
refactor: remove using unnecessary FrozenAttribute.