Tools: Add tmux support to run_in_terminal_window.sh

Added in an option so that if running SITL in a tmux session it will open a new window in tmux.
More or less an alternate option to screen.
It will detect if its running in a tmux session by checking the $TMUX and $TERM env variables.
I put it before other options because when I am running a tmux session even in a GUI environment
I would prefer a new Tmux window compared to a new terminal.
This will only run if youre already in a tmux session it will not launch a new session.

Tools/autotest/run_in_terminal_window.sh

@@ -28,6 +28,8 @@ if [ -n "$SITL_RITW_TERMINAL" ]; then
   printf "%q " "$@" >>"$FILEPATH"
   chmod +x "$FILEPATH"
   $SITL_RITW_TERMINAL "$FILEPATH" &
+elif [ "$TERM" = "screen" ] && [ -n "$TMUX" ]; then
+  tmux new-window -dn "$name" "$*"
 elif [ -n "$DISPLAY" -a -n "$(which osascript)" ]; then
   osascript -e 'tell application "Terminal" to do script "'"$* "'"'
 elif [ -n "$DISPLAY" -a -n "$(which xterm)" ]; then