TASK: Enable escaping of string path in Arrays::getValueByPath

It is now possible to escape the dot in the path of Arrays::getValueByPath.
With this you get array keys, which have a dot.

Example:
```
$foo = ['bar.baz' => 'value'];
$path = 'bar\.baz';
```

Neos.Utility.Arrays/Classes/Arrays.php

@@ -194,7 +194,31 @@ public static function array_reduce(array $array, string $function, $initial = n
     public static function getValueByPath(array &$array, $path)
     {
         if (is_string($path)) {
-            $path = explode('.', $path);
+            if (strpos($path, '\\.') === -1) {
+                $path = explode('.', $path);
+            } else {
+                $pattern = '#(?<!\\\\)((?:\\\\\\\\)*)\\.#';
+                $split = preg_split($pattern, $path, -1, PREG_SPLIT_NO_EMPTY|PREG_SPLIT_DELIM_CAPTURE);
+                $split = array_reduce(
+                    $split,
+                    static function ($result, $value) {
+                        $lastIndex = count($result) - 1;
+                        if ($lastIndex >= 0 && preg_match('#^\\\\*$#', $value)) {
+                            $result[$lastIndex] = $result[$lastIndex] . $value;
+                        } else {
+                            $result[] = $value;
+                        }
+                        return $result;
+                    },
+                    []
+                );
+                $path = array_map(
+                    static function ($value) {
+                        return str_replace(['\\\\','\\.'], ['\\','.'], $value);
+                    },
+                    $split
+                );
+            }
         } elseif (!is_array($path)) {
             throw new \InvalidArgumentException('getValueByPath() expects $path to be string or array, "' . gettype($path) . '" given.', 1304950007);
         }

Neos.Utility.Arrays/Tests/Unit/ArraysTest.php

@@ -80,6 +80,30 @@ public function getValueByPathReturnsTheValueOfANestedArrayByFollowingTheGivenPa
         $this->assertSame($expectedResult, $actualResult);
     }
 
+    /**
+     * @test
+     */
+    public function getValueByPathReturnsTheValueOfANestedArrayByFollowingTheGivenPathIfPathIsStringWithEscapedDots()
+    {
+        $path = 'Foo.Bar\.Baz.2';
+        $array = ['Foo' => ['Bar.Baz' => [2 => 'the value']]];
+        $expectedResult = 'the value';
+        $actualResult = Arrays::getValueByPath($array, $path);
+        self::assertSame($expectedResult, $actualResult);
+    }
+
+    /**
+     * @test
+     */
+    public function getValueByPathReturnsTheValueOfANestedArrayByFollowingTheGivenPathIfPathIsStringWithBackslashes()
+    {
+        $path = 'Foo.Bar\\\\.Baz.2';
+        $array = ['Foo' => ['Bar\\' => ['Baz' => [2 => 'the value']]]];
+        $expectedResult = 'the value';
+        $actualResult = Arrays::getValueByPath($array, $path);
+        self::assertSame($expectedResult, $actualResult);
+    }
+
     /**
      * @test
      * @expectedException \InvalidArgumentException