Improve performance and behavior of ListMap and ListSet

Makes the immutable `ListMap` and `ListSet` collections more alike one another, both in their semantics and in their performance.

In terms of semantics, makes the `ListSet` iterator return the elements in their insertion order, as `ListMap` already does. While, as mentioned in SI-8985, `ListMap` and `ListSet` doesn't seem to make any guarantees in terms of iteration order, I believe users expect `ListSet` and `ListMap` to behave in the same way, particularly when they are implemented in the exact same way.

In terms of performance, `ListSet` has a custom builder that avoids creation in O(N^2) time. However, this significantly reduces its performance in the creation of small sets, as its requires the instantiation and usage of an auxilliary HashSet. As `ListMap` and `ListSet` are only suitable for small sizes do to their performance characteristics, the builder is removed, the default `SetBuilder` being used instead.

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