Replay the request to avoid subscription races

The subscription timing is slightly unpredictable due to React's
effect execution order. This way initial requests won't get lost. The
response$ is multicast already due to `share()`, so I don't expect any
negative consequences. (famous last words)

Author: weltenwort

x-pack/plugins/infra/public/utils/data_search/use_data_search_request.ts

@@ -6,7 +6,7 @@
  */
 
 import { useCallback } from 'react';
-import { OperatorFunction, Subject } from 'rxjs';
+import { OperatorFunction, ReplaySubject } from 'rxjs';
 import { share, tap } from 'rxjs/operators';
 import {
   IKibanaSearchRequest,
@@ -47,7 +47,7 @@ export const useDataSearch = <
 }) => {
   const { services } = useKibanaContextForPlugin();
   const requests$ = useObservable(
-    () => new Subject<ParsedDataSearchRequestDescriptor<Request, Response>>(),
+    () => new ReplaySubject<ParsedDataSearchRequestDescriptor<Request, Response>>(1),
     []
   );