Feature: Improve UI/Ux of suggestions for DataSearch and CategorySearch

**Issue Type:**

Enhancement

**Platform:**

ReactiveSearch for Web

**Description:**

Incorporate different UI/Ux improvements to make the suggestions UI more palatable:
1. Use more symmetry in how the suggestions are displayed,
2. Add subtle highlighting,
3. Check for spacing and padding.

**Screenshots:**

**Minimal reproduction of the problem with instructions:**

**Reactivesearch version:** x.y.z

**Browser:** [all | Chrome XX | Firefox XX | Edge XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]

**Anything else:**