Let number of rows per page be configurable for DataTable

[kevinlang]

When using Kino.DataTable in livebook, it will only show 10 rows at a time. This should be configurable.

As far as I can tell it is hardcoded to 10 here. https://github.com/livebook-dev/kino/blob/5d9bee0da23aedc1ebd859659f968552fda5d6dc/lib/kino/table.ex#L48

[josevalim]

Yes, we are going to redesign data tables sooner than later, and we plan to make this configurable.