[EuiEmptyPrompt] Is too tall with no easy way to customize

[cchaos]

When the new layouts were introduced the styles were optimized for instances that had lots of content. However for simple prompts like errors or "no results", the min-height is too tall and is a bit awkward. I've run into it myself, but I've also seen others hack their way on top of it: elastic/kibana#128925 (review)

Example of being able to not have anything but a title:

[elizabetdev]

I can remove the min-height, it was a stupid idea to add it. 😬

The purpose was to make the empty/loading/error experience look better but I guess it is better if consumers add their own min-height for these scenarios.

Screen.Recording.2022-04-04.at.01.10.06.PM.mp4

So I'll remove the min-height from the component and improve this example to add a custom min-height.