fix(测试跟踪): 维护人改为责任人

--bug=1008036 --user=刘瑞斌 【github#7816】升级到v1.14.2之后，导入的测试用例，不管是excel还是xmind，都不能统计在用例维护人分布上，显示为空 https://www.tapd.cn/55049933/s/1070457

Closes #7816

frontend/src/i18n/en-US.js

@@ -1795,7 +1795,7 @@ export default {
       review_progress: "Review Progress",
       case_count: "Statistics of the number of use cases",
       relevance_case: "Relevance Case",
-      case_maintenance: "Use case maintainer distribution",
+      case_maintenance: "Use case person responsible distribution",
       bug_count: "Statistics of remaining defects",
       case_review: "Use case review",
       review_rate: "Rate",

frontend/src/i18n/zh-CN.js

@@ -1803,7 +1803,7 @@ export default {
       review_progress: "评审进度",
       case_count: "用例数量统计",
       relevance_case: "关联用例数量统计",
-      case_maintenance: "用例维护人分布",
+      case_maintenance: "用例责任人分布",
       bug_count: "遗留缺陷统计",
       case_review: "用例评审",
       review_rate: "评审率",

frontend/src/i18n/zh-TW.js

@@ -1804,7 +1804,7 @@ export default {
       review_progress: "評審進度",
       case_count: "用例數量統計",
       relevance_case: "關聯用例數量統計",
-      case_maintenance: "用例維護人分布",
+      case_maintenance: "用例責任人分布",
       bug_count: "遺留缺陷統計",
       case_review: "用例評審",
       review_rate: "評審率",