fix(接口测试): 修复引用的case包含文件时可以修改的缺陷

--bug=1019480 --user=王孝刚
【接口测试】github#19536，接口自动化模块，引用的接口case也可以修改请求体的关联文件，但修改后不会生效。应该禁止修改
https://www.tapd.cn/55049933/s/1305635

frontend/src/business/components/api/definition/components/body/ApiBodyFileUpload.vue

@@ -7,9 +7,10 @@
          :http-request="upload"
          :beforeUpload="uploadValidate"
          :file-list="parameter.files"
+         :disabled = "isReadOnly"
          ref="upload">
 
-         <div class="upload-default" v-if="!isReadOnly">
+         <div class="upload-default">
            <i class="el-icon-plus"/>
          </div>
            <div class="upload-item" slot="file" slot-scope="{file}">
@@ -18,7 +19,7 @@
               <!--<span v-if="!disabled" class="el-upload-list__item-delete" @click="handleDownload(file)">-->
                <!--<i class="el-icon-download"/>-->
                <!--</span>-->
-              <span v-if="!disabled" class="el-upload-list__item-delete" @click="handleRemove(file)">
+              <span v-if="!disabled && !isReadOnly" class="el-upload-list__item-delete" @click="handleRemove(file)">
                 <i class="el-icon-delete"/>
               </span>
              </span>