Issue #3460100 by TR: Add declare(strict_types=1) to all tests

tests/src/Functional/TypedDataFormWidget/BrokenWidgetTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Functional\TypedDataFormWidget;
 
 use Drupal\Core\Plugin\Context\ContextDefinition;

tests/src/Functional/TypedDataFormWidget/DatetimeWidgetTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Functional\TypedDataFormWidget;
 
 use Drupal\Core\Datetime\DrupalDateTime;

tests/src/Functional/TypedDataFormWidget/FormWidgetBrowserTestBase.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Functional\TypedDataFormWidget;
 
 use Drupal\Core\TypedData\TypedDataTrait;

tests/src/Functional/TypedDataFormWidget/SelectWidgetTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Functional\TypedDataFormWidget;
 
 use Drupal\Core\Plugin\Context\ContextDefinition;

tests/src/Functional/TypedDataFormWidget/TextInputWidgetTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Functional\TypedDataFormWidget;
 
 use Drupal\Core\Plugin\Context\ContextDefinition;

tests/src/Functional/TypedDataFormWidget/TextareaWidgetTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Functional\TypedDataFormWidget;
 
 use Drupal\Core\Plugin\Context\ContextDefinition;

tests/src/Kernel/DataDefinitionFetcherTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Core\Field\FieldStorageDefinitionInterface;

tests/src/Kernel/DataFetcherAutocompleteTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Core\Field\FieldStorageDefinitionInterface;

tests/src/Kernel/DataFetcherTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Core\Entity\TypedData\EntityDataDefinition;

tests/src/Kernel/DataFilterTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Core\Datetime\Entity\DateFormat;

tests/src/Kernel/IpAddressDataTypeTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Core\TypedData\DataDefinition;

tests/src/Kernel/PlaceholderResolverTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Component\Render\HtmlEscapedText;

tests/src/Kernel/TextDataTypeTest.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Kernel;
 
 use Drupal\Core\TypedData\DataDefinition;

tests/src/Traits/BrowserTestHelpersTrait.php

 <?php
 
+declare(strict_types=1);
+
 namespace Drupal\Tests\typed_data\Traits;
 
 use Behat\Mink\Element\NodeElement;