feat: 新增多个服务类及工具类，重构部分代码结构

重构服务类结构，将分散的服务统一整合到service包下
新增ProjectConstant常量类及多个实体服务类
添加SecurityUtils安全工具类和BeanCacher工具类
优化部分UI控件和转换器的实现

client/src/main/java/com/ecep/contract/service/EmployeeService.java

@@ -8,6 +8,8 @@ import com.ecep.contract.vm.EmployeeViewModel;
 
 public class EmployeeService implements ViewModelService<Employee, EmployeeViewModel> {
 
+    public static final int DEFAULT_SYSTEM_EMPLOYEE_ID = 26;
+
     public Employee findByName(String name) {
         // TODO Auto-generated method stub
         throw new UnsupportedOperationException("Unimplemented method 'findByName'");
@@ -28,5 +30,10 @@ public class EmployeeService implements ViewModelService<Employee, EmployeeViewM
         throw new UnsupportedOperationException("Unimplemented method 'search'");
     }
 
+    public Employee findByCode(String personCode) {
+        // TODO Auto-generated method stub
+        throw new UnsupportedOperationException("Unimplemented method 'findByCode'");
+    }
+
 
 }