Improve the visual appearance of OVAL test details

[jan-cerny]

Is your feature request related to a problem? Please describe.
Recently, OVAL test details subwindow has been improved (eg. in #235 and #239). It now contains better structured data. However, the visual appearance of this section could be better.

Describe the solution you'd like
Use better styles, leverage styles that PF offers, employ different colors, improve element width and height.

Describe alternatives you've considered
I haven't consider any alternative.

Additional context
No