Add priority to protected branch (#32286)

## Solves

Currently for rules to re-order them you have to alter the creation
date. so you basicly have to delete and recreate them in the right
order. This is more than just inconvinient ...

## Solution

Add a new col for prioritization

## Demo WebUI Video

https://github.com/user-attachments/assets/92182a31-9705-4ac5-b6e3-9bb74108cbd1


---
*Sponsored by Kithara Software GmbH*

models/migrations/v1_23/v310.go

@@ -0,0 +1,16 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_23 //nolint
+
+import (
+	"xorm.io/xorm"
+)
+
+func AddPriorityToProtectedBranch(x *xorm.Engine) error {
+	type ProtectedBranch struct {
+		Priority int64 `xorm:"NOT NULL DEFAULT 0"`
+	}
+
+	return x.Sync(new(ProtectedBranch))
+}