Log metrics as bar charts

[AlekseySh]

We may compute metrics on different categories, see docs.

The problem appears when we log and plot this metrics. They are shown on different plots, so it's hard to compare different categories. It would be great to see those metrics as bar chars for easier side-by-side comparison.

Let's update a categories example so we have a function that creates a bar chart (as an image in np format) based on provided metrics dictionary, so we can visualize it.

After it's done, we can add this functionality to Pipelines Logging.

[AlekseySh]

We are still looking for someone who can take care of this issue :)