Working on SIGSTOP and SIGCONT handling

SIGSTOP and SIGCONT are POSIX signals for stopping and resuming a running process. I’m working on adding handling for these, so you can safely pause and unpause rasterminal at any time. This is a lot of work, since until now, we just set up the terminal on program start and cleaned up when the program exited. There’s a lot of quirks and weird scenarios that I have to handle, for example if another signal gets sent while cleaning up the terminal for SIGSTOP. I’m trying to catch as many edge cases by just doing random things while using the program and also with the help of AI to come up with potentially uncaught scenarios.