snapmatcher: various errors in pipelines

Snapmatch returns various errors in pipelines:

when version match score is 0, overall score is still calculated as 50, so snapmatch tries to download info about a non-existent "" version (empty string) from Debian Snapshot API
libpam is not found, but it corresponds to "pam" package in Debian, need to set an alias
there is an error when trying to display some log messages, because a dict key is treated as an object property

Edited Oct 03, 2022 by Alberto Pianon