support/scripts/pkg-stats: add is_actual_package() and rework has_valid_infra()

support/scripts/pkg-stats: add is_actual_package() and rework has_valid_infra()

has_valid_infra() is incorrectly named; it probably should be named
is_actual_package(), and has_valid_infra() would be changed to
actually represent having an actual infra.

This resolves packages reporting as having no valid package infra and
cleans up reporting cases of CPE and CVEs where there isn't a valid version
or package definition outside Buildroot

Cc: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Matthew Weber <matthew.weber@collins.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>