Add CSS for right-to-left language input fields (#5021)

src/pretix/static/pretixbase/scss/_rtl.scss

@@ -47,3 +47,9 @@ html.rtl {
     }
   }
 }
+
+input[lang=ar], textarea[lang=ar], div[lang=ar], pre[lang=ar],
+input[lang=hw], textarea[lang=hw], div[lang=hw], pre[lang=hw] {
+  /* Keep list of languages in sync with pretix._base_settings.LANGUAGES_RTL */
+  direction: rtl;
+}