1. fixedTest: Remove some unneeded layers of function calls.
2. Don't add a modified version of `black` to the global pkgs set.
Tests should not affect the pkgs of the tested system modules.
Fix the driver build script instead by adding an extra arg to the
call to `black`.
This improves debugging and experimenting by making it easy to compose fine-grained
scenarios that have specific tests and features enabled.
The VM test output now includes the subtest name and duration.
Remove the 'raise Exception()' hack for interactive mode.
Run 'banlist-and-restart' test before 'backups'. This speeds up the test
by avoiding an extra shutdown of all bitcoin-related services.