Change to vertical navbar layout for secondary navbar for repo/user/admin settings (#24246)

Co-Author: @wxiaoguang 

This is the first step of #24229. And this PR will only includes html
changes, and followed by other PRs that fine tune css and change to
submenus.

After:

Admin Level

<img width="1400" alt="Screen Shot 2023-04-21 at 10 07 16"
src="https://user-images.githubusercontent.com/17645053/233523870-f848b61d-056a-4b41-9760-a9a49fea1fe8.png">

User Level

<img width="1422" alt="Screen Shot 2023-04-21 at 10 07 23"
src="https://user-images.githubusercontent.com/17645053/233523878-979adb20-a657-43d9-99a6-ad414010c0ef.png">

Repo Level

<img width="1404" alt="Screen Shot 2023-04-21 at 10 07 07"
src="https://user-images.githubusercontent.com/17645053/233523863-337440bd-c03a-4dfd-87fa-cef40300bfe0.png">

---------

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

templates/repo/settings/branches.tmpl

@@ -1,9 +1,5 @@
-{{template "base/head" .}}
-<div role="main" aria-label="{{.Title}}" class="page-content repository settings edit">
-	{{template "repo/header" .}}
-	{{template "repo/settings/navbar" .}}
-	<div class="ui container">
-		{{template "base/alert" .}}
+{{template "repo/settings/layout_head" (dict "ctxData" . "pageClass" "repository settings edit")}}
+	<div class="repo-setting-content">
 		{{if .Repository.IsArchived}}
 			<div class="ui warning message">
 				{{.locale.Tr "repo.settings.archive.branchsettings_unavailable"}}
@@ -94,7 +90,6 @@
 			{{end}}
 		{{end}}
 	</div>
-</div>
 
 <div class="ui gitea-confirm-modal delete modal">
 	<div class="header">
@@ -107,4 +102,4 @@
 	{{template "base/modal_actions_confirm" .}}
 </div>
 
-{{template "base/footer" .}}
+{{template "repo/settings/layout_footer" .}}