[data.search] Respect search request track_total_hits value (#215245)

## Summary

Fixes https://github.com/elastic/kibana/issues/212946.

Updates `getSearchParamsFromRequest` to respect `track_total_hits` if it
is included in the `body` portion of the search request.

### 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

src/platform/plugins/shared/data/common/search/search_source/fetch/get_search_params.test.ts

@@ -26,7 +26,7 @@ describe('getSearchParams', () => {
     expect(searchParams.preference).toBe('aaa');
   });
 
-  test('extracts track total hits', () => {
+  test('extracts track total hits from request', () => {
     const getConfig = getConfigStub({
       [UI_SETTINGS.COURIER_SET_REQUEST_PREFERENCE]: 'custom',
       [UI_SETTINGS.COURIER_CUSTOM_REQUEST_PREFERENCE]: 'aaa',
@@ -44,6 +44,27 @@ describe('getSearchParams', () => {
     expect(searchParams.query).toStrictEqual([{ query: '123', language: 'kql' }]);
   });
 
+  test('extracts track total hits from body', () => {
+    const getConfig = getConfigStub({
+      [UI_SETTINGS.COURIER_SET_REQUEST_PREFERENCE]: 'custom',
+      [UI_SETTINGS.COURIER_CUSTOM_REQUEST_PREFERENCE]: 'aaa',
+    });
+    const searchParams = getSearchParamsFromRequest(
+      {
+        body: {
+          query: { bool: { filter: [] } },
+          track_total_hits: false,
+          size: 500,
+        },
+        index: 'abc',
+      },
+      { getConfig }
+    );
+    expect(searchParams.index).toBe('abc');
+    expect(searchParams.track_total_hits).toBe(false);
+    expect(searchParams.query).toMatchInlineSnapshot(`undefined`);
+  });
+
   test('sets expand_wildcards=all if data view has allowHidden=true', () => {
     const getConfig = getConfigStub({
       [UI_SETTINGS.COURIER_SET_REQUEST_PREFERENCE]: 'custom',

src/platform/plugins/shared/data/common/search/search_source/fetch/get_search_params.ts

@@ -35,10 +35,12 @@ export function getSearchParamsFromRequest(
   const searchParams = { preference: getEsPreference(getConfig) };
   const dataView = typeof searchRequest.index !== 'string' ? searchRequest.index : undefined;
   const index = dataView?.title ?? `${searchRequest.index}`;
+  const trackTotalHits = searchRequest.track_total_hits ?? searchRequest.body.track_total_hits;
 
   // @ts-expect-error elasticsearch@9.0.0 `query` types don't match (it seems like it's been wrong here for a while)
   return {
     ...searchRequest,
+    track_total_hits: trackTotalHits,
     index,
     ...(dataView?.getAllowHidden() && { expand_wildcards: 'all' }),
     ...searchParams,