feat(gear-requirements): 添加图片展示字段

在 GearRequirements、GearRequirementsBo、GearRequirementsVo以及对应的
Mapper XML 文件中增加 image 字段，用于支持图片展示功能。

gear-oa/src/main/resources/mapper/oa/GearRequirementsMapper.xml

@@ -13,6 +13,7 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         <result property="description" column="description"/>
         <result property="deadline" column="deadline"/>
         <result property="status" column="status"/>
+        <result property="image" column="image"/>
         <result property="remark" column="remark"/>
         <result property="accessory" column="accessory"/>
         <result property="createBy" column="create_by"/>