Fixed 'img' tags, removed utf8_encode since it's deprecated and readded echoRaw from textarea widget

src/Method/FormContext.php

@@ -38,7 +38,7 @@ class FormContext implements FormContextInterface
         $this->values = $request->getParsedBody() ?: [];
 
         if ( ! $this->values ) {
-            $content = utf8_encode((string) $request->getBody());
+            $content = mb_convert_encoding((string) $request->getBody(), 'UTF-8');
 
             if ( $content && ( $json = json_decode($content, true) ) ) {
                 $this->values = $json;