Add a new pylance api to grab the outputChannel

[bschnurr]

• This allows pylance to share the output channel "python language server"

[karthiknadig]

Should we be doing it like this? I feel like the channel could be moved into Jedi so, we only create it for Jedi. and then you won't need the API. You can just create the Output channel for yourself.

[bschnurr]

ok. i'll try that

[bschnurr]

@karthiknadig delaying the creation of the output window break other calls that assume its there.. one place is trying to auto select it on startup. i'm just going leave the python language server window to always be there.