Restore full functionality of OAuth2 server [skip ci]

common/tests/fixtures/OauthRefreshTokensFixture.php

@@ -0,0 +1,19 @@
+<?php
+declare(strict_types=1);
+
+namespace common\tests\fixtures;
+
+use common\models\OauthRefreshToken;
+use yii\test\ActiveFixture;
+
+class OauthRefreshTokensFixture extends ActiveFixture {
+
+    public $modelClass = OauthRefreshToken::class;
+
+    public $dataFile = '@root/common/tests/fixtures/data/oauth-refresh-tokens.php';
+
+    public $depends = [
+        OauthSessionFixture::class,
+    ];
+
+}

common/tests/fixtures/OauthSessionFixture.php

@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace common\tests\fixtures;
 
 use common\models\OauthSession;

common/tests/fixtures/data/oauth-refresh-tokens.php

@@ -0,0 +1,2 @@
+<?php
+return [];