CAUSEWAY-3641: DataTableInteractive#Memento don't require Executions on Deserialization

[andi-huber]

• [x] Use the (now) serializable DataTable to model table data
• [ ] Invent some freeze mechanism for DataTable, that is, once we have the cell data, don't require to recompute (via executions)

As we do want to pave the way for a generic search field, we need all the table rows, hence table paging is modeled as a view into the full DataTable.