Make tagcloud vis to use kibana font family

[sulemanof]

Describe the feature:

We need to get rid of Open Sans font family in Tag Cloud visualization and use inherited one from kibana app.
The problem is d3 tagcloud renderer can't built a chart well without an explicit font family set in config and makes tags overlap each other:

Firstly mentioned here: #77910 (review)

Describe a specific use case for the feature:

[stratoula]

I did a quick investigation on this bug and it seems that it is a regression that was caused on 7.10.
So here is a tagcloud graph on 7.9:

And here is the same graph on 7.10:

Maybe it was introduced with the new tagcloud renderer? cc @sulemanof

Note: If I change on a 7.9 branch the Open Sans with the Inter UI it works like a charm but on 7.10 no so I assume that it is independent of the font change.