Convert an AsyncIterable<Uint8Array> into an AsyncIterable<Uint8Array[]> (an array of lines chunked together based on buffer size) split on lf and also suppressing trailing cr.

lf and trailing cr is removed from the returned lines. As this is line-oriented data, if the last line is empty (the last byte was a line feed, splitting into one extra line), it is suppressed.

Implementation attempts to minimize object creation.