faster implementation of transpose/0

[pkoppstein]

The following is much faster (3x in some instances) than the current def in builtins.jq

def transpose: [range(0; map( length ) | max) as $i | [.[][$i]]];

Even better would be to add stream-oriented versions of min/0 and max/0:

def min(s): reduce s as $x (first(s); if $x < . then $x else . end);
def max(s): reduce s as $x (first(s); if $x > . then $x else . end);

and then:

def transpose: [range(0; max(.[]|length)) as $i | [.[][$i]]];

[pkoppstein]

Resolved by #2679