UX: minor tweaks to table columns (#37845)

https://meta.discourse.org/t/invisible-button-text-layout-misalignment-on-horizon-theme/396180

This area will be reworked more extensively soon, so this commit is just
a small bandaid to improve it in the meantime.

app/assets/stylesheets/admin/admin_report_table.scss

@@ -9,7 +9,6 @@
 
     .table .admin-report-table-cell:last-child,
     .table .admin-report-table-header:last-child {
-      width: 80%;
       text-align: right;
     }
   }
@@ -102,6 +101,10 @@
   .admin-report-table-header.topic_title {
     width: 80%;
   }
+
+  .admin-report-table-cell.number {
+    width: 6ch;
+  }
 }
 
 .admin-report.trending-search {
@@ -116,6 +119,16 @@
   .admin-report-table-cell.term {
     @include ellipsis;
   }
+
+  .admin-report-table-cell.percent {
+    width: 5ch;
+    text-align: right;
+  }
+
+  .admin-report-table-cell.number.searches {
+    width: 6ch;
+    text-align: right;
+  }
 }
 
 .admin-report.moderators-activity {

frontend/discourse/admin/components/admin-report-table-header.gjs

@@ -49,7 +49,7 @@ export default class AdminReportTableHeader extends Component {
           @icon={{this.sortIcon}}
           @translatedLabel={{unless @label.htmlTitle @label.title}}
           @translatedTitle={{this.sortButtonTitle}}
-          class="btn-primary btn-transparent sort-btn"
+          class="btn-transparent --primary sort-btn"
         >
           {{#if @label.htmlTitle}}
             <span class="d-button-label">{{htmlSafe @label.htmlTitle}}</span>