Add Klatre, a grab-bag common lisp utility package, including
definitions for `comment`, `posp`, `chunk-list`, and `mapconcat`.
The name traces its lineage back to Abseil, a similar grab-bag utility
library for C++ - abseiling is what you do to go down a route after
you're done climbing it, and klatre is norwegian for "to climb"
Change-Id: I5efd91d8af827883679ce1a2eed3229b28e082ac
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1346
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
