fix: kill hook when the command is stuck

[ldez]

The context.WithTimeout doesn't kill a command when the command is stuck because CombinedOutput is waiting for a "pause".

The previous implementation was able to stop the hook if the script was too long, but not stuck on one element (cf test: sleepy.sh).

But it was not able to stop the hook if the script was waiting for a long (never-ending) process (cf test: sleeping_beauty.sh).

I modified the code to add a timer that kills the current process if the timeout is reached.

This implementation has another advantage: the output of the hook will be live streamed to the console.

Fixes #2468

[dmke]

LGTM