FINERACT-1954: Waive null pointer and due date fix

- [x] Fix Waive due date handle
- [x] Fix null pointer exception
- [x] Integration test

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/domain/Loan.java

@@ -1081,7 +1081,12 @@ public class Loan extends AbstractAuditableWithUTCDateTimeCustom {
                 transactionDate = loanCharge.getDueLocalDate();
             }
         } else if (loanCharge.isInstalmentFee()) {
-            transactionDate = loanCharge.getInstallmentLoanCharge(loanInstallmentNumber).getRepaymentInstallment().getDueDate();
+            LocalDate repaymentDueDate = loanCharge.getInstallmentLoanCharge(loanInstallmentNumber).getRepaymentInstallment().getDueDate();
+            if (repaymentDueDate.isAfter(DateUtils.getBusinessLocalDate())) {
+                transactionDate = DateUtils.getBusinessLocalDate();
+            } else {
+                transactionDate = repaymentDueDate;
+            }
         }
 
         scheduleGeneratorDTO.setRecalculateFrom(transactionDate);

fineract-loan/src/main/java/org/apache/fineract/portfolio/loanaccount/domain/LoanInstallmentCharge.java

@@ -25,6 +25,7 @@ import jakarta.persistence.ManyToOne;
 import jakarta.persistence.Table;
 import java.math.BigDecimal;
 import org.apache.fineract.infrastructure.core.domain.AbstractPersistableCustom;
+import org.apache.fineract.interoperation.util.MathUtil;
 import org.apache.fineract.organisation.monetary.domain.MonetaryCurrency;
 import org.apache.fineract.organisation.monetary.domain.Money;
 import org.apache.fineract.portfolio.loanaccount.data.LoanInstallmentChargeData;
@@ -168,7 +169,7 @@ public class LoanInstallmentCharge extends AbstractPersistableCustom implements
     }
 
     public boolean isPending() {
-        return !(isPaid() || isWaived());
+        return !MathUtil.isZero(this.amountOutstanding);
     }
 
     public boolean isChargeAmountpaid(MonetaryCurrency currency) {