[BASOP-CI] add split comparison for ltv files

As discussed in various calls, this adds a cmdl arg to pytest that enables splitting of the long test vector files before the comparison to the reference is done. Goal with this is to get a better understanding of the overall PEAQ values for the ltv files and especially what parts of the files contribute most to a possibly bad rating.

⚠️ discontinued in favour of !2089 (merged)