fix gpgsm issues with gnupg-2.3
    
    The output of gpgsm changed slightly in gnupg-2.3, causing the git tests
    for x509 signatures to be skipped.  Update the tests to use the
    machine-parseable --with-colons output.
    
    It also appears that we need to reload the gpg-agent in order to pick up
    the changes the test library makes to the trustlist.txt file.  It might
    be better to store that file with the other gpg files in the test suite
    rather than generating it.
    
    While we're at it, reload all the gpg components rather than just
    gpg-agent.  Adjust the earlier gpgconf kill to use the 'all' keyword as
    well.
    
    Next up, gpgsm removed a debug line from it's output which exposes a
    problem in git's gpg-interface code.  The git code presumes that the
    '[GNUPG:] SIG_CREATED' line will follow a newline.  That is no longer
    true.  The debug line was removed from GnuPG in a6d2f3133 (sm: Replace
    some debug message by log_error or log_info, 2020-04-21).
    
    Finally, a minor bug in gpgsm causes the error message returned when a
    certificate is not found to differ from previous versions¹.  Extend the
    grep pattern in the test suite to catch both error messages.
    
    ¹ https://lists.gnupg.org/pipermail/gnupg-devel/2021-November/034991.html