Merge branch '5.2' into 5.x

* 5.2:
  [Finder] Fix gitignore regex build with "**"
  Fixed deprecation warnings about passing null as parameter
  [Security] Keep Bulgarian wording consistent across all texts.
  Migrate configuration file for PHP CS Fixer 2.19/3.0
  [Form] Replace broken ServerParams mock
  [Mailer] Fix SES API call with UTF-8 Addresses

Author: fabpot

Parser.php

@@ -624,7 +624,7 @@ private function getNextEmbedBlock(int $indentation = null, bool $inSequence = f
         $data = [];
 
         if ($this->getCurrentLineIndentation() >= $newIndent) {
-            $data[] = substr($this->currentLine, $newIndent);
+            $data[] = substr($this->currentLine, $newIndent ?? 0);
         } elseif ($this->isCurrentLineEmpty() || $this->isCurrentLineComment()) {
             $data[] = $this->currentLine;
         } else {