linalyse: change check-pkgs reporting to improve readability

Change check-pkgs report to include total number of packages
checked, number of packages found on the system, and number
of missing packages and missing required dependent packages.
linalyse: change check-platform reporting to improve readability

Change check-platform report to include total number of system
files checked, number of system files found on the system, and
number of missing system files.