Extend CacheStream interface to allow for Serializable lambdas

Recently it was found that we could add multiple overrides of a method where it was using a FunctionalInterface but also make that interface extend Serializable. This would allow for provided lambdas to be instantly serializable since the JVM will pick the most specific argument.

Example:

CacheStream filter(Predicate<? super R> predicate);

vs

CacheStream filter(SerializablePredicate<? super R> predicate);