Better Form Stats (#567)

* Better Form Stats

* fix lint

* submission timer store in localstorage

* Update test case for stats

* remove extra code

* fix form stats

* on restart remove timer

* fix resetTimer function name

* Improve form timer

* Fix timer after form validation error + polish UI

---------

Co-authored-by: Julien Nahum <julien@nahum.net>

api/app/Http/Requests/FormStatsRequest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Http\Requests;
+
+use Illuminate\Foundation\Http\FormRequest;
+use Carbon\Carbon;
+
+class FormStatsRequest extends FormRequest
+{
+    public function authorize()
+    {
+        return true;
+    }
+
+    public function rules()
+    {
+        return [
+            'date_from' => 'required|date',
+            'date_to' => 'required|date|after_or_equal:date_from',
+        ];
+    }
+
+    public function withValidator($validator)
+    {
+        $validator->after(function ($validator) {
+            if (Carbon::parse($this->date_from)->diffInMonths(Carbon::parse($this->date_to)) > 3) {
+                $validator->errors()->add('date_range', 'Date range exceeds 3 months. Please select a shorter period.');
+            }
+        });
+    }
+}