Re-add --parent-term-exit

[dreamgineer]

Is your feature request related to a problem? Please describe.
I believe 7557064 was not meant to delete parent-term-exit from the code.

Describe the solution you'd like
Re-add pieces of code that made it happen.

Describe alternatives you've considered
.bashrc based conditional exit

Additional context
My current workaround is:

[ -f ~/.inshellisense/bash/init.sh ] && source ~/.inshellisense/bash/init.sh                                                                       
is                                                                                                                                                 
clear                                                                                                                                              
[ "$ISTERM" != "1" ] && exit