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/org/settings/labels.tmpl

@@ -1,10 +1,5 @@
-{{template "base/head" .}}
-<div role="main" aria-label="{{.Title}}" class="page-content organization settings labels">
-	{{template "org/header" .}}
-	<div class="ui container">
-		<div class="ui grid">
-			{{template "org/settings/navbar" .}}
-				<div class="ui twelve wide column content">
+{{template "org/settings/layout_head" (dict "ctxData" . "pageClass" "organization settings labels")}}
+				<div class="org-setting-content">
 					<div class="ui grid">
 						<div class="left floated twelve wide column">
 							{{$.locale.Tr "org.settings.labels_desc" | Str2html}}
@@ -17,13 +12,8 @@
 					</div>
 					<div class="ui divider"></div>
 					{{template "repo/issue/labels/label_new" .}}
-					{{template "base/alert" .}}
 					{{template "repo/issue/labels/label_list" .}}
 				</div>
-			</div>
-		</div>
-	</div>
-</div>
-
 {{template "repo/issue/labels/edit_delete_label" .}}
-{{template "base/footer" .}}
+{{template "org/settings/layout_footer" .}}
+