Unify REPL and "Run Selection/Line in Python terminal" terminals?

[cbrnr]

With the new smart Shift+Enter feature, it is now very convenient to run a line (or a selection of lines) of code in the interactive interpreter. After hitting Shift+Enter (or selecting "Run Selection/Line in Python terminal"), a new terminal titled "Python" opens with the interactive interpreter, which accepts intput from this command.

However, I was wondering if I can manually start this terminal (i.e., the Python one, which is connected to the "Run Selection/Line in Python terminal" action). I found the "Python: Start REPL" action, which launches the interactive interpreter, but this terminal does not accept input from Shift+Enter.

Would it be possible to unify these two ways of starting the interactive Python interpreter and/or running code? Or maybe let users decide to which terminal they want to send their Shift+Enter commands? This would be very convenient, because right now the only way to kickstart the interpreter for sending commands is to actually send the first line of code.

[brettcannon]

I opened #22242 as "Start REPL" should probably work.