Adding signal, termios, process group, modern pty management features

[LeChatP]

Describe the solution you'd like
The objective here is to have an entire and full-featured command execution management with sr command. As It should handle signal, termios, process group, and a better pty management. These features requires particular security management as each of them can be exploited to take indirect or direct control on the privileged process.

Describe alternatives you've considered
Today, only sudo-rs present such features with great code quality. So I asked them if it is possible to share the same base code about command execution feature here