[EuiDataGrid] [EuiLoading] While data is being fetched for a table, what should I display?

[j-m]

I know there's EuiLoadingSpinner and EuiLoadingContent, but neither feel quite right to me; they both feel too small, especially if the page is designed for a table with 100 rows.

Could we introduce a component called EuiLoadingBlock that takes width and height props? I feel this would also be good for components like images or other custom components that have fixed (or predictable) dimensions. Ideally, the props would assume px but also allow percentage or relative units. I think this also fills a gap not covered by EuiLoadingContent as, by design and rightly so, it does not accept more than 10 lines.

If this isn't the EUI way then fair enough, but I'd be interested in hearing other people's designs

Also, just my 2 pence, EuiLoadingContent should probably be renamed to EuiLoadingText

[j-m]

Whoops, forgot to search for existing issues first, sorry
#4181
#3474