fix: dashboard list page bugs while in mode 3 (#110568)

* fix infinite scroll when using folder tree view in dashboard page inside folders with more than 50 items

* fix off-by-one error when fetching in list view

public/app/features/browse-dashboards/api/services.test.ts

@@ -44,6 +44,7 @@ describe('browse-dashboards services', () => {
         location: 'abc-123',
         from: expectedFrom,
         limit: PAGE_SIZE,
+        offset: expectedFrom,
       });
     });
   });

public/app/features/browse-dashboards/api/services.ts

@@ -51,6 +51,7 @@ export async function listDashboards(parentUID?: string, page = 1, pageSize = PA
     location: parentUID || 'general',
     from: (page - 1) * pageSize, // our pages are 1-indexed, so we need to -1 to convert that to correct value to skip
     limit: pageSize,
+    offset: (page - 1) * pageSize,
   });
 
   return dashboardsResults.view.map((item) => {

public/app/features/search/service/types.ts

@@ -41,6 +41,7 @@ export interface SearchQuery {
   starred?: boolean;
   permission?: PermissionLevelString;
   deleted?: boolean;
+  offset?: number;
 }
 
 export interface DashboardQueryResult {

public/app/features/search/service/unified.ts

@@ -202,7 +202,7 @@ export class UnifiedSearcher implements GrafanaSearcher {
       totalRows: meta.count ?? first.length,
       view,
       loadMoreItems: async (startIndex: number, stopIndex: number): Promise<void> => {
-        loadMax = Math.max(loadMax, stopIndex);
+        loadMax = Math.max(loadMax, stopIndex + 1);
         if (!pending) {
           pending = getNextPage();
         }
@@ -260,6 +260,10 @@ export class UnifiedSearcher implements GrafanaSearcher {
     uri += `?query=${encodeURIComponent(query.query ?? '*')}`;
     uri += `&limit=${query.limit ?? pageSize}`;
 
+    if (query.offset) {
+      uri += `&offset=${query.offset}`;
+    }
+
     if (!isEmpty(query.location)) {
       uri += `&folder=${query.location}`;
     }