fix(项目管理): 通用配置变量搜索默认提示优化

--bug=1018571 --user=李玉号 【项目管理】环境配置-通用配置变量搜索默认提示优化
https://www.tapd.cn/55049933/s/1270926

framework/sdk-parent/frontend/src/components/environment/commons/ApiScenarioVariables.vue

@@ -2,7 +2,7 @@
   <div>
     <div>
       <div style="padding-bottom: 10px;float: left">
-        <el-input :placeholder="$t('commons.search_by_name')" size="mini" v-model="selectVariable"
+        <el-input :placeholder="$t('api_test.search_by_variables')" size="mini" v-model="selectVariable"
                   @change="filter"
                   @keyup.enter="filter">
         </el-input>

framework/sdk-parent/frontend/src/i18n/lang/en-US.js

@@ -1217,6 +1217,7 @@ const message = {
     buttons: {
       to_xml: "To xml",
     },
+    search_by_variables: "Search by variable",
     case_jump_message: "The jump use case has been removed！",
     scenario_jump_message: "The jumped scene has been deleted！",
     is_continue: "Is continue",

framework/sdk-parent/frontend/src/i18n/lang/zh-CN.js

@@ -1227,6 +1227,7 @@ const message = {
     buttons: {
       to_xml: "转xml结构",
     },
+    search_by_variables: "根据变量名搜索",
     case_jump_message: "跳转的用例已经删除！",
     scenario_jump_message: "跳转的场景已经删除！",
     is_continue: "是否继续",

framework/sdk-parent/frontend/src/i18n/lang/zh-TW.js

@@ -1224,6 +1224,7 @@ const message = {
     buttons: {
       to_xml: "轉xml結構",
     },
+    search_by_variables: "根據變量名搜索",
     case_jump_message: "跳轉的用例已經刪除！",
     scenario_jump_message: "跳轉的場景已經刪除！",
     is_continue: "是否繼續",