fix: allowing sorting Contract Definitions by creation date

extensions/control-plane/store/sql/contract-definition-store-sql/src/main/java/org/eclipse/edc/connector/controlplane/store/sql/contractdefinition/schema/postgres/ContractDefinitionMapping.java

@@ -26,6 +26,7 @@
 public class ContractDefinitionMapping extends TranslationMapping {
     public ContractDefinitionMapping(ContractDefinitionStatements statements) {
         add("id", statements.getIdColumn());
+        add("createdAt", statements.getCreatedAtColumn());
         add("accessPolicyId", statements.getAccessPolicyIdColumn());
         add("accessPolicy", statements.getAccessPolicyIdColumn());
         add("contractPolicyId", statements.getContractPolicyIdColumn());