Validation::getError() wildcard

Signed-off-by: Andrey Pyzhikov <5071@mail.ru>

user_guide_src/source/changelogs/v4.2.0.rst

@@ -37,6 +37,7 @@ Changes
 - The current version of Content Security Policy (CSP) outputs one nonce for script and one for style tags. The previous version outputted one nonce for each tag.
 - The process of sending cookies has been moved to the ``Response`` class. Now the ``Session`` class doesn't send cookies, set them to the Response.
 - Validation. Changed generation of errors when using fields with a wildcard (*). Now the error key contains the full path. See :ref:`validation-getting-all-errors`.
+- ``Validation::getError()`` when using a wildcard will return all found errors matching the mask as a string.
 
 Deprecations
 ************