Scan embedded_templates to locate additional functions

Add a check for `\Twig\Node\ModuleNode` instances when traversing the nodes.

When found, grab the `embedded_templates` attribute, an array of `\Twig\Node\ModuleNode` instances for each embed or include in a template.
Then loop and scan these as we do child nodes.

This resolves #5 and allows for nested blocks to be scanned for functions.

Author: tehbeard

src/TwigFunctionsScanner.php

@@ -15,6 +15,7 @@
 use Twig\Environment;
 use Twig\Source;
 use Twig\Node\Expression\FunctionExpression;
+use Twig\Node\ModuleNode;
 
 class TwigFunctionsScanner implements FunctionsScannerInterface
 {
@@ -66,6 +67,14 @@ private function extractGettextFunctions($token, string $filename, array &$funct
         foreach ($token->getIterator() as $subToken) {
             $this->extractGettextFunctions($subToken, $filename, $functions);
         }
+        
+        if($token instanceof ModuleNode){
+            $embeddedTemplates = $token->getAttribute('embedded_templates');
+            foreach($embeddedTemplates as $embed)
+            {
+                $this->extractGettextFunctions($embed, $filename, $functions);
+            }
+        }
     }
 
     public function scan(string $code, string $filename): array