Correction of EuiLoadingElastic animation to be compliant with the brand guidelines

[ek-so]

Is your feature request related to a problem? Please describe.
Currently we have an animated logo spinner which looks in a way that is not compliant with the brand standards — the usage of Elastic logo on black background is not permitted without a white border.

Describe the solution you'd like

• Ideally, we use the same animation that brand does — but without shift to the right, and looped.
• Make sure we use euiCanAnimate to enable an option to switch off the animation on the user's side for accessibility.

Additional context
We could think of the possibility to implement it using json (e.g. Lottie?), if that's how the desired outcome would be easier to get. In this case, @ek-so can help with getting such a json.