execution commands for contributed REPLs

[amunger]

shift+enter should execute the input box code as it does in jupyter IWs.
consider how to switch between enter vs shift+enter

[anthonykim1]

Also discussed today the need to figure out shift+enter and enter behavior when both Python extension and Jupyter extension are installed. Should be configurable, not sure what are exactly needed to make this happen though.

[anthonykim1]

Need: #212427 to properly handle executing on enter and thus allowing Python extension to figure out whether something is a complete or incomplete Python command.

[anthonykim1]

We should be good once microsoft/vscode-python#23442 is merged. Handling execute on enter like the traditional interactive REPL in terminal from Python itself closely as we can.

Current state: user has to explicitly set "interactiveWindow.executeWithShiftEnter": false in order to execute via Enter Keypress when using interactive Native REPL.
They won't have to manually change this setting once the default value for interactiveWindow.execute is changed to True in core.