[Unified Search] Improve Preview UX for long field names in filter modal

[timductive]

When using long field names the Preview UX becomes very difficult to read.

Do we actually need this preview space?
Can we make it easier to see the ORs and ANDs for very long fields?

[elasticmachine]

Pinging @elastic/kibana-visualizations @elastic/kibana-visualizations-external (Team:Visualizations)

[stratoula]

cc @andreadelrio any suggestions here?

[andreadelrio]

The Preview section was found to be useful in the usability testing we conducted, though that research wasn’t extensive (small number of testers). Also note that with this new form layout, long field names inevitably get cut off in the inputs. The Preview was introduced as a way to alleviate this as it displays all field names, operators, and values without any truncation. What we could do is give users the option to toggle the visibility of the Preview.

Having said that I think we can improve the way in which we are displaying text in this section. Here’s an idea

[sophiec20]

Please dbl check use of bold or semi-bold is appropriate for the page. I've seen similar long passages where it just looks like you are being shouted at.