[FEATURES] Accelerate Docker Image Loading with Fluid

[lizzzcai]

What feature you'd like to add:

Hi Fluid team, want to check if Fluid support preload/cache docker image into the nodes. If yes, is there any tutorial? If not, is it possible to support preLoad docker images to the nodes by Fluid so that Pod can start up faster?

For example, support docker image in the Dataset concept.

Why is this feature needed:

1. As in some cases, users tend to put everything into the docker image (including the dataset).
2. It will be a good feature in serverless use cases as it can reduce cold start time.

Thanks.