Better print out for stream output

[elferherrera]

Corrected bug with channel. Using sync_channel was blocking some external commands, like rg.

Things that still need correction:

• When using cat (probably only windows) the prompt gets mangled and it can only be seen as bytes. It goes back to normal after typing something and pressing enter
  

• Python commands are not sent to stdout. If we send python -c "print('hello')" the output is missed. However we can enter a python shell without problem

• The use of ^ for marking and external command. Now git cannot be used because there is a git command in engine-q

[sophiajt]

In Linux, passing args to Python seems okay:

〉python3 -c "print('hello')" | each { $"($it) is good" }
[hello
 is good]