Completion detail view: was streamed

[jacekzimonski]

could you please show on the completion detail view if the completion was streamed or not?

[jacekzimonski]

@guillaq Do you know if we expose that information anywhere in Completion? Going thru the code in backend and looks like it's now exposed.

[jacekzimonski]

@anyacherniss @guillaq
PR was created: #460
It's Frontend and Backend so @guillaq please review.