[Discover] Deactivate client-side pagination for ES|QL results (#189715)

- Closes https://github.com/elastic/kibana/issues/189489

## Summary

This PR deactivates client-side pagination for ES|QL results so they
will not be split into pages but shown all at once in the grid. Affected
pages: Discover, Dashboard.

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

packages/kbn-unified-data-table/src/components/data_table.tsx

@@ -575,14 +575,15 @@ export const UnifiedDataTable = ({
       valueToStringConverter,
       componentsTourSteps,
       isPlainRecord,
-      pageIndex: paginationObj?.pageIndex,
-      pageSize: paginationObj?.pageSize,
+      pageIndex: isPaginationEnabled ? paginationObj?.pageIndex : 0,
+      pageSize: isPaginationEnabled ? paginationObj?.pageSize : displayedRows.length,
     }),
     [
       componentsTourSteps,
       darkMode,
       dataView,
       isPlainRecord,
+      isPaginationEnabled,
       displayedRows,
       expandedDoc,
       onFilter,

src/plugins/discover/public/application/main/components/layout/discover_documents.tsx

@@ -417,6 +417,7 @@ function DiscoverDocumentsComponent({
                 onUpdateRowHeight={onUpdateRowHeight}
                 isSortEnabled={true}
                 isPlainRecord={isEsqlMode}
+                isPaginationEnabled={!isEsqlMode}
                 rowsPerPageState={rowsPerPage ?? getDefaultRowsPerPage(services.uiSettings)}
                 onUpdateRowsPerPage={onUpdateRowsPerPage}
                 maxAllowedSampleSize={getMaxAllowedSampleSize(services.uiSettings)}

src/plugins/discover/public/embeddable/components/saved_search_grid.tsx

@@ -104,6 +104,7 @@ export function DiscoverGridEmbeddable(props: DiscoverGridEmbeddableProps) {
     >
       <DiscoverGridMemoized
         {...gridProps}
+        isPaginationEnabled={!gridProps.isPlainRecord}
         totalHits={props.totalHitCount}
         setExpandedDoc={setExpandedDoc}
         expandedDoc={expandedDoc}

test/functional/apps/discover/group2_data_grid3/_data_grid_pagination.ts

@@ -14,7 +14,14 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
   const esArchiver = getService('esArchiver');
   const kibanaServer = getService('kibanaServer');
   const dataGrid = getService('dataGrid');
-  const PageObjects = getPageObjects(['settings', 'common', 'discover', 'header', 'timePicker']);
+  const PageObjects = getPageObjects([
+    'settings',
+    'common',
+    'discover',
+    'header',
+    'timePicker',
+    'dashboard',
+  ]);
   const defaultSettings = {
     defaultIndex: 'logstash-*',
     'discover:rowHeightOption': 0, // single line
@@ -22,6 +29,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
   const testSubjects = getService('testSubjects');
   const retry = getService('retry');
   const security = getService('security');
+  const dashboardAddPanel = getService('dashboardAddPanel');
 
   describe('discover data grid pagination', function describeIndexTests() {
     before(async () => {
@@ -119,5 +127,45 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       expect((await dataGrid.getDocTableRows()).length).to.be(10); // as in the saved search
       await dataGrid.checkCurrentRowsPerPageToBe(10);
     });
+
+    it('should not split ES|QL results into pages', async () => {
+      const rowsPerPage = 5;
+      const savedSearchESQL = 'testESQLPagination';
+      await kibanaServer.uiSettings.update({
+        ...defaultSettings,
+        'discover:sampleRowsPerPage': rowsPerPage,
+        hideAnnouncements: true,
+      });
+
+      await PageObjects.common.navigateToApp('discover');
+      await PageObjects.discover.waitUntilSearchingHasFinished();
+
+      // expect pagination to be present for data view mode
+      expect((await dataGrid.getDocTableRows()).length).to.be(rowsPerPage);
+      await dataGrid.checkCurrentRowsPerPageToBe(rowsPerPage);
+      await testSubjects.existOrFail('pagination-button-0');
+
+      await PageObjects.discover.selectTextBaseLang();
+      await PageObjects.header.waitUntilLoadingHasFinished();
+      await PageObjects.discover.waitUntilSearchingHasFinished();
+
+      // expect no pagination for ES|QL mode
+      expect((await dataGrid.getDocTableRows()).length).to.above(rowsPerPage);
+      await testSubjects.missingOrFail('pagination-button-0');
+
+      await PageObjects.discover.saveSearch(savedSearchESQL);
+
+      await PageObjects.common.navigateToApp('dashboard');
+
+      await PageObjects.dashboard.clickNewDashboard();
+      await PageObjects.timePicker.setDefaultAbsoluteRange();
+      await dashboardAddPanel.clickOpenAddPanel();
+      await dashboardAddPanel.addSavedSearch(savedSearchESQL);
+      await PageObjects.header.waitUntilLoadingHasFinished();
+
+      // expect no pagination for ES|QL mode on Dashboard
+      expect((await dataGrid.getDocTableRows()).length).to.above(rowsPerPage);
+      await testSubjects.missingOrFail('pagination-button-0');
+    });
   });
 }