Having these named differently than the test itself mostly creates
unecessary confusion and makes writing logic against the tests harder
so let's rename the testsuite-xx units and scripts to just use the
test name itself.
It never worked, but the fail was masked by missing set -e, see the
previous commit.
Also, throw env into the test container and dump the environment on
container start, to make potential failures easier to debug.
It already required a lot of workarounds, since the busybox utilities
often work differently than their "full" counterparts, and putting
the container together using our "tools" is quite simple anyway.
