Currently we start up and thus compile policy packs one by one.  When
multiple policy packs need to be loaded, this increases the start up
time substantially.  In previous tests plugins took ~1-3s to start up,
so having multiple of these the time adds up quickly.

Loading them in parallel will help reduce the startup time here.

…rallel

We have utf-8 characters in the command line, and should be supporting
testing those.  Explicity specify utf-8 encoding when reading the
integration test files, so we don't fail on some platform where the
default encoding might not allow those characters.