Update testdox for remaining unit tests

tests/unit/Mapper/StringMapperTest.php

@@ -18,6 +18,7 @@ use PHPUnit\Framework\TestCase;
 #[TestDox('String Mapper (Unit tests)')]
 class StringMapperTest extends TestCase
 {
+    #[TestDox('map() succeeds when field is present and string')]
     public function testMapSucceedsWhenFieldIsPresentAndString(): void
     {
         $result = ['test_field' => 'test_value'];
@@ -25,6 +26,7 @@ class StringMapperTest extends TestCase
         $this->assertEquals('test_value', $mapper->map($result), 'String value not returned correctly');
     }
 
+    #[TestDox('map() succeeds when field is present and not string')]
     public function testMapSucceedsWhenFieldIsPresentAndNotString(): void
     {
         $result = ['a_number' => 6.7];
@@ -32,6 +34,7 @@ class StringMapperTest extends TestCase
         $this->assertEquals('6.7', $mapper->map($result), 'Number value not returned correctly');
     }
 
+    #[TestDox('map() succeeds when field is not present')]
     public function testMapSucceedsWhenFieldIsNotPresent(): void
     {
         $mapper = new StringMapper('something_else');