DataTable Slots

Leptos slot regions for DataTable composition.

• Replacing the default toolbar, footer, or loading/empty overlays.
• Custom expandable row detail panels via DataTableRowDetail.

Nest slot children on DataTable: DataTableToolbarSlot, DataTableFooterSlot, DataTableEmptyView, DataTableNoResultsView, DataTableLoadingView, and DataTableRowDetail. Wire side effects through DataTableEvents and read table state with use_data_table_table_state.