xbps-install -n prints nothing for installed/download size if 0

[classabbyamp]

for a metapackage like removed-packages, installed-size is 0, so xbps-install -n prints nothing for that field:

xbps/bin/xbps-install/transaction.c

Lines 69 to 72 in e82437f

	if (isize)
	printf(" %ju", isize);
	if (dsize)
	printf(" %ju", dsize);

removed-packages-0.1.20241127_1 update aarch64 https://repo-fastly.voidlinux.org/current/aarch64 7973

combined with download-size possibly being 0, this makes parsing the output harder/impossible because there aren't a consistent number of fields per line.

this should probably print 0 or -, but having json output (like xbps-query is getting) would also be nice for simpler parsing by other programs