feat: add step 5 page and update active stepper logic in poultry farm inspection

doc: some utils in core

packages/core/lib/utils/text_input_formatter/separator_input_formatter.dart

@@ -0,0 +1,33 @@
+import 'package:flutter/services.dart';
+import 'package:intl/intl.dart';
+
+
+/// A text input formatter that formats numbers with a separator.
+/// Example:
+/// ```dart
+/// SeparatorInputFormatter()
+/// ```
+class SeparatorInputFormatter extends TextInputFormatter {
+  final NumberFormat _formatter;
+
+  SeparatorInputFormatter() : _formatter = NumberFormat('#,###');
+
+  @override
+  TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
+    if (newValue.text.isEmpty) {
+      return newValue;
+    }
+    String tmpText = newValue.text;
+    String cleanedText = tmpText.replaceAll(RegExp(r'\D'), '');
+    int? number = int.tryParse(cleanedText);
+    if (number == null) {
+      return oldValue;
+    }
+    String formattedText = _formatter.format(number);
+    int selectionIndex = formattedText.length;
+    return TextEditingValue(
+      text: formattedText,
+      selection: TextSelection.collapsed(offset: selectionIndex),
+    );
+  }
+}