Convert .grouped to return an Iterator instead of a Stream?

[lihaoyi]

That would better match up with the collections in the standard library, which all return Iterator. Current inefficient workaround is .toArray.grouped.map(ByteVector.view), though with a bit more boilerplate less wasteful version could be written

[mpilquist]

👍 for either 1.2 or 2.0 -- whatever comes next. Let's keep this issue open until we decide breaking binary compatibility makes sense.