refactor(接口测试): 修复前后置操作配置名称过长时导致后面的操作按钮未对齐的缺陷

--bug=1011510 --user=王孝刚
【接口测试】case编辑/api-test-前/后置操作配置-名称过长时导致后面的操作按钮未对齐
https://www.tapd.cn/55049933/s/1123244

frontend/src/business/components/api/definition/components/step/JmxStep.vue

@@ -30,7 +30,7 @@
              :filter-node-method="filterNode"
              @node-drag-end="allowDrag"
              draggable ref="generalSteps" class="ms-step-tree-cell">
-       <span class="custom-tree-node father" slot-scope="{node,data}" style="width: 100%">
+       <span class="custom-tree-node father" slot-scope="{node,data}" style="width: calc(100% - 20px);">
         <!--前置脚本-->
          <div v-if="tabType === 'pre'">
            <ms-jsr233-processor