Convenient way for pasting multi-line commands into REPL

[Elizaveta239]

Currently there's no convenient way to paste multi line commands from a file into the REPL. MicroPython inserts them line by line and it breaks indents inside the command.

Ideallly, PyCham should understand that a user inserts a multi-line command and automatically switch into the Paste mode and fix indents for the user.