dev add complaint entity

src/main/java/ru/soune/nocopy/exception/ComplaintNotFoundException.java

@@ -0,0 +1,7 @@
+package ru.soune.nocopy.exception;
+
+public class ComplaintNotFoundException extends RuntimeException {
+    public ComplaintNotFoundException(String message) {
+        super(message);
+    }
+}

src/main/java/ru/soune/nocopy/exception/DuplicateComplaintException.java

@@ -0,0 +1,7 @@
+package ru.soune.nocopy.exception;
+
+public class DuplicateComplaintException extends RuntimeException {
+  public DuplicateComplaintException(String message) {
+    super(message);
+  }
+}