Fix some regex dialect compatibility issues

RES-609 DEVSIX-6329

Author: MatthiasValvekens

commons/src/main/java/com/itextpdf/commons/actions/producer/ProducerBuilder.java

@@ -62,8 +62,9 @@ public final class ProducerBuilder extends AbstractITextConfigurationEvent {
      * <code>${</code> and ended with <code>}</code> without <code>}</code> character inside.
      * These substrings are interpreted as placeholders and the first group is the content of the
      * placeholder.
+     * Note: The escape on '}' is necessary for regex dialect compatibility reasons.
      */
-    private static final String PATTERN_STRING = "\\$\\{([^}]*)}";
+    private static final String PATTERN_STRING = "\\$\\{([^}]*)\\}";
     private static final Pattern PATTERN = Pattern.compile(PATTERN_STRING);
 
     private static final Map<String, IPlaceholderPopulator> PLACEHOLDER_POPULATORS;

pdftest/src/main/java/com/itextpdf/test/LoggerHelper.java

@@ -86,7 +86,8 @@ static void failWrongTotalCount(int expected, int actual, Description descriptio
     * */
     static boolean equalsMessageByTemplate(String message, String template) {
         if (template.contains("{") && template.contains("}")) {
-            String templateWithoutParameters = Pattern.quote(template).replace("''", "'").replaceAll("\\{[0-9]+?}", "\\\\E(.)*?\\\\Q");
+            // Note: The escape on '}' is necessary for regex dialect compatibility reasons.
+            String templateWithoutParameters = Pattern.quote(template).replace("''", "'").replaceAll("\\{[0-9]+?\\}", "\\\\E(.)*?\\\\Q");
             Pattern p = Pattern.compile(templateWithoutParameters, Pattern.DOTALL);
             return p.matcher(message).matches();
         } else {