fix debian match bugs before implementing it in the compliance pipeline for preliminary checks

see OSTC/planning/ip-compliance#72

• we decided to split the compliance pipeline in 2 parts
• the 1st part is intended to do only a preliminary check to find out which packages deserve an urgent review, based on debian matching (low or no debian matching = needs immediate revies)
• the 1st part will be run very frequently, so it needs to be very fast to execute
• the new debian snapmatcher command is very slow, and it cannot be optimized, because the slowness depends on debian snapshot server limitations
• thus we decided to keep also the "old" match command (even if it's less accurate and not reproducible), to be used only for the preliminary check in the 1st part of the pipeline

However, the "old" match command has some bugs that need to be fixed before implementing it in the said pipeline.

• #21 (closed) : AlienPackage.expand() method returns error when checking aliensrc pkgs with tagged source files
• #22 (closed) : inconsistency in error handling and logging in match command