Add examine essentials.

[aochmann]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
We can add examine essentials like those: https://github.com/prjseal/Searching-In-Umbraco-v8/blob/e32d57a955051de520618d6234a63d9a44d93b41/Searching.Site/Extensions/StringArrayExtensions.cs#L21

Describe alternatives you've considered
Question is if we want to keep it in this repo or creating dedicated just for Examine Essentials 🤔

Additional context