Starting since this commit 36cdd5c3cd
there is an ASAN stack-buffer-overflow error because we append a NULL
terminator beyond the length of memory allocated.
Reviewed by: Monty and Nayuta Yanagisawa
This patch adds support for right aligned strings and numbers.
Left alignment is left as an exercise for anyone needing it.
MDEV-25612 "Assertion `to <= end' failed in process_args" fixed.
(Was caused by the original version of this patch)