feat: add infinite query builder with example

fix(query): updateQueryFn refetch when stale and update state of builders when widget is mounted

packages/fl_query/lib/src/widgets/query_builder.dart

@@ -18,7 +18,6 @@ class QueryBuilder<DataType, ErrorType, KeyType> extends StatefulWidget {
   final QueryFn<DataType> queryFn;
   final ValueKey<KeyType> queryKey;
 
-  final QueryBuilderFn builder;
   final DataType? initial;
 
   final RetryConfig retryConfig;
@@ -30,6 +29,7 @@ class QueryBuilder<DataType, ErrorType, KeyType> extends StatefulWidget {
 
   // widget specific
   final bool enabled;
+  final QueryBuilderFn<DataType, ErrorType, KeyType> builder;
 
   const QueryBuilder(
     this.queryKey,
@@ -44,7 +44,7 @@ class QueryBuilder<DataType, ErrorType, KeyType> extends StatefulWidget {
     this.enabled = true,
     super.key,
   }) : assert(
-          enabled && jsonConfig != null,
+          (jsonConfig != null && enabled) || jsonConfig == null,
           'jsonConfig is only supported when enabled is true',
         );
 
@@ -63,7 +63,7 @@ class _QueryBuilderState<DataType, ErrorType, KeyType>
   StreamSubscription<ErrorType>? errorSubscription;
 
   void update(_) {
-    setState(() {});
+    if (mounted) setState(() {});
   }
 
   Future<void> initialize() async {
@@ -115,6 +115,8 @@ class _QueryBuilderState<DataType, ErrorType, KeyType>
       removeListener?.call();
       initialize();
       return;
+    } else if (oldWidget.enabled != widget.enabled && widget.enabled) {
+      query!.fetch();
     }
     if (oldWidget.queryFn != widget.queryFn) {
       query!.updateQueryFn(widget.queryFn);
@@ -147,7 +149,8 @@ class _QueryBuilderState<DataType, ErrorType, KeyType>
       DiagnosticsProperty<ValueKey<KeyType>>('queryKey', widget.queryKey),
     );
     properties.add(
-      DiagnosticsProperty<QueryBuilderFn>('builder', widget.builder),
+      DiagnosticsProperty<QueryBuilderFn<DataType, ErrorType, KeyType>>(
+          'builder', widget.builder),
     );
     properties.add(DiagnosticsProperty<DataType>('initial', widget.initial));
     properties.add(