feat: Add sorting by exclusive labels (issue priority) (#33206)

Fix #2616

This PR adds a new sort option for exclusive labels.

For exclusive labels, a new property is exposed called "order", while in
the UI options are populated automatically in the `Sort` column (see
screenshot below) for each exclusive label scope.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

options/label/Advanced.yaml

@@ -22,49 +22,60 @@ labels:
     description: Breaking change that won't be backward compatible
   - name: "Reviewed/Duplicate"
     exclusive: true
+    exclusive_order: 2
     color: 616161
     description: This issue or pull request already exists
   - name: "Reviewed/Invalid"
     exclusive: true
+    exclusive_order: 3
     color: 546e7a
     description: Invalid issue
   - name: "Reviewed/Confirmed"
     exclusive: true
+    exclusive_order: 1
     color: 795548
     description: Issue has been confirmed
   - name: "Reviewed/Won't Fix"
     exclusive: true
+    exclusive_order: 3
     color: eeeeee
     description: This issue won't be fixed
   - name: "Status/Need More Info"
     exclusive: true
+    exclusive_order: 2
     color: 424242
     description: Feedback is required to reproduce issue or to continue work
   - name: "Status/Blocked"
     exclusive: true
+    exclusive_order: 1
     color: 880e4f
     description: Something is blocking this issue or pull request
   - name: "Status/Abandoned"
     exclusive: true
+    exclusive_order: 3
     color: "222222"
     description: Somebody has started to work on this but abandoned work
   - name: "Priority/Critical"
     exclusive: true
+    exclusive_order: 1
     color: b71c1c
     description: The priority is critical
     priority: critical
   - name: "Priority/High"
     exclusive: true
+    exclusive_order: 2
     color: d32f2f
     description: The priority is high
     priority: high
   - name: "Priority/Medium"
     exclusive: true
+    exclusive_order: 3
     color: e64a19
     description: The priority is medium
     priority: medium
   - name: "Priority/Low"
     exclusive: true
+    exclusive_order: 4
     color: 4caf50
     description: The priority is low
     priority: low

options/locale/locale_en-US.ini

@@ -1655,6 +1655,8 @@ issues.label_archived_filter = Show archived labels
 issues.label_archive_tooltip = Archived labels are excluded by default from the suggestions when searching by label.
 issues.label_exclusive_desc = Name the label <code>scope/item</code> to make it mutually exclusive with other <code>scope/</code> labels.
 issues.label_exclusive_warning = Any conflicting scoped labels will be removed when editing the labels of an issue or pull request.
+issues.label_exclusive_order = Sort Order
+issues.label_exclusive_order_tooltip = Exclusive labels in the same scope will be sorted according to this numeric order.
 issues.label_count = %d labels
 issues.label_open_issues = %d open issues/pull requests
 issues.label_edit = Edit