Displays conversion confidence scores and grades

[fabianofranz]

RHELAI-4250

Adds a new section to the Knowledge notebook to display confidence scores and grades to each document conversion.

[fabianofranz]

@alimaredia @JustinXHale ptal

[fabianofranz]

[anastasds]

I wonder whether we should really consider all conversions with confidence less than the mean should be called "low confidence".

I have to think about whether this would really be rigorous, but we could construct a confidence interval based on individual confidence scores as a measure of how well we think it converts any given page on average, and then label conversions below the interval.

What is done here would be probably be a fine place to start, though - probably better to start out being underconfident than overconfident.