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.
The qemu seabios firmware disables serial console line wrapping. Let's
make sure we re-enable it again when we reset a terminal to some sane
defaults.
To avoid potentially blocking on writing to the terminal, we put it
in nonblocking mode and add a timeout of 50ms.
Forward journal to console, since we won't have any journal from initrd
and shutdown/exit initrd phases. Also, mention
systemd.journald.max_level_console=debug that is very handy for
debugging initrd shenanigans, but don't use it by default since it
sends a _lot_ of stuff to the serial console, which slows down the test
a lot.