Add regression test for unique() column type resolution (#1787)

Confirms string()->unique() correctly resolves to string type.
Related to barryvdh/laravel-ide-helper#1747

Co-authored-by: Youssef Mansour <[email protected]>

tests/Console/ModelsCommand/migrations/____users_unique_table.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class UsersUniqueTable extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('users_unique', function (Blueprint $table) {
+            $table->increments('id');
+            $table->string('name');
+            $table->string('email')->unique();
+            $table->string('password');
+            $table->timestamps();
+        });
+    }
+}