Be more tolerant to invalid JSON when parsing dashboards for indexing (#114040)

* Tags can only be string array.

* Be more lenient when parsing dashboard. Parse what we can, don't error out easily.

* Check element before parsing, log unexpected types.

pkg/storage/unified/search/dashboard.go

@@ -261,7 +261,10 @@ func (s *DashboardDocumentBuilder) BuildDocument(ctx context.Context, key *resou
 		value = rsp.Value
 	}
 
-	summary, err := dashboard.ReadDashboard(bytes.NewReader(value), s.DatasourceLookup)
+	summary, err := dashboard.ReadDashboardWithLogContext(bytes.NewReader(value), s.DatasourceLookup, map[string]any{
+		"document": fmt.Sprintf("%s/%s/%s/%s", key.GetNamespace(), key.GetGroup(), key.GetResource(), key.GetName()),
+		"rv":       rv,
+	})
 	if err != nil {
 		return nil, err
 	}