feat: add job fair region type functionality and improve job fair detail pages

- Introduced job fair region type selection in EditModal and PublicJobFairList components.
- Enhanced JobFairDetail page to display job fair region type using DictTag.
- Updated API types to include jobFairRegionType for better data handling.
- Created new JobPortal pages for displaying job fair details with improved styling.
- Added CSS styles for job fair detail and list pages to enhance user experience.
- Implemented loading states and error handling for job fair data fetching.

src/pages/JobPortal/JobFair/Detail/index.less

@@ -0,0 +1,62 @@
+@import '../../theme.less';
+
+.portal-job-fair-detail-page {
+  .job-fair-detail-content {
+    .jp-page-container();
+    padding-top: 24px;
+    padding-bottom: 56px;
+  }
+
+  .job-fair-back {
+    margin: 0 0 12px;
+    padding: 0;
+  }
+
+  .job-fair-detail-card {
+    .jp-card-base();
+
+    .ant-card-body {
+      padding: 32px;
+    }
+  }
+
+  .job-fair-detail-title-row {
+    margin-bottom: 26px;
+
+    .ant-tag {
+      margin-bottom: 12px;
+    }
+
+    .ant-typography {
+      margin: 0;
+      color: @jp-text-primary;
+    }
+  }
+
+  .job-fair-detail-introduction {
+    margin-top: 28px;
+
+    .ant-typography {
+      color: @jp-text-primary;
+    }
+
+    p {
+      margin-bottom: 0;
+      white-space: pre-wrap;
+      color: @jp-text-secondary;
+      line-height: 1.85;
+    }
+  }
+}
+
+@media (max-width: 576px) {
+  .portal-job-fair-detail-page {
+    .job-fair-detail-content {
+      padding: 16px 12px 36px;
+    }
+
+    .job-fair-detail-card .ant-card-body {
+      padding: 20px;
+    }
+  }
+}