Merge branch '4.4' into 5.4

* 4.4:
  Improve DE translations for Form/Validator
  [WebProfilerBundle] Fix dark theme selected line highlight color & reuse css vars
  [Mime] Check that the path is a file in the DataPart::fromPath
  [Cache] do not pass null to strlen()

Author: derrabus

Resources/translations/validators.de.xlf

@@ -12,7 +12,7 @@
             </trans-unit>
             <trans-unit id="30">
                 <source>The CSRF token is invalid. Please try to resubmit the form.</source>
-                <target>Der CSRF-Token ist ungültig. Versuchen Sie bitte das Formular erneut zu senden.</target>
+                <target>Der CSRF-Token ist ungültig. Versuchen Sie bitte, das Formular erneut zu senden.</target>
             </trans-unit>
             <trans-unit id="99">
                 <source>This value is not a valid HTML5 color.</source>