[ADF-2150] improved queryBody mechanism (#2852)

* [ADF-2150] changed query body parameter to a function

* [ADF-2150] added an example page where to try change query body

* [ADF-2150] improved queryBody mechanism

* [ADF-2150] fixed content node test

* [ADF-2150] extended docs added another way to use the query node

* [ADF-2150] fixed test for search on content node

* [ADF-2150] added some improvements to service config

* [ADF-2150] changed the documentation accordingly

* [ADF-2150] added PR changes

* [ADF-2150] fixed jdoc

* [ADF-2150] added checkbox to switch from service approach to input object approach

* [ADF-2150] fixed build error on demo shell

lib/core/services/service.module.ts

@@ -47,6 +47,7 @@ import { TranslateLoaderService } from './translate-loader.service';
 import { TranslationService } from './translation.service';
 import { UploadService } from './upload.service';
 import { UserPreferencesService } from './user-preferences.service';
+import { SearchConfigurationService } from './search-configuration.service';
 
 @NgModule({
     imports: [],
@@ -81,7 +82,8 @@ import { UserPreferencesService } from './user-preferences.service';
         SharedLinksApiService,
         SitesService,
         DiscoveryApiService,
-        CommentProcessService
+        CommentProcessService,
+        SearchConfigurationService
     ],
     exports: [
     ]