[run_in_new_terminal] Create a wrapper script automatically if we are given a list or tuple

[heapcrash]

This is needed for the gdb.debug and gdb.attach rewrite that I have planned.

Ends up looking like this:

>>> context.log_level='debug'
>>> run_in_new_terminal(['sh', '-c', 'zsh -il'])
[DEBUG] Created script for new terminal:
    #!/Users/heapcrash/.pyenv/versions/3.8.3/bin/python3.8
    import os
    os.execve('/bin/sh', ['sh', '-c', 'zsh -il'], os.environ)
[DEBUG] Launching a new terminal: ['/usr/local/bin/tmux', 'splitw', '-F#{pane_pid}', '-P', '/var/folders/45/y3yh_pws51qd8dfx007hf6br0000gn/T/tmp8945_lax']
59563

[heapcrash]

All CI passed except a single failure in corefile which is transient