Categorize admin settings sidebar panel (#26030)

This PR reorganize and categorize the admin settings sidebar panel into
groups:

- User Accounts, User Emails, Organizations, Authentication Sources ->
Identity & Access
- Repositories, Packages -> Code Assets
- Webhooks, Applications -> Integrations

Before:

<img width="1346" alt="Screen Shot 2023-07-21 at 10 30 28"
src="https://github.com/go-gitea/gitea/assets/17645053/e0c5ae83-464f-4aaa-8bab-2c5258c9278d">

After:

all configurable settings enabled (package, oauth, webhook)

<img width="1153" alt="Screen Shot 2023-07-21 at 10 27 30"
src="https://github.com/go-gitea/gitea/assets/17645053/88acf3f5-0623-4307-8654-69c654d80874">

all configurable settings disabled (package, oauth, webhook)

<img width="1391" alt="Screen Shot 2023-07-21 at 10 25 19"
src="https://github.com/go-gitea/gitea/assets/17645053/9e13aa60-e75c-4077-afd6-3da9e0ae18dd">

only oauth enabled

<img width="1323" alt="Screen Shot 2023-07-21 at 10 26 23"
src="https://github.com/go-gitea/gitea/assets/17645053/ce4f9ec0-b141-4d5e-ac13-46d001724dc5">

only webhook enabled

<img width="1350" alt="Screen Shot 2023-07-21 at 10 26 55"
src="https://github.com/go-gitea/gitea/assets/17645053/702491bd-083e-44fa-82bc-52c4571e54ac">

2 files changed, 54 insertions, 26 deletions

diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 94ae490981..24be7e0fc3 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -2627,10 +2627,13 @@ teams.invite.description = Please click the button below to join the team.
 
 [admin]
 dashboard = Dashboard
+identity_access = Identity & Access
 users = User Accounts
 organizations = Organizations
+assets = Code Assets
 repositories = Repositories
 hooks = Webhooks
+integrations = Integrations
 authentication = Authentication Sources
 emails = User Emails
 config = Configuration
diff --git a/templates/admin/navbar.tmpl b/templates/admin/navbar.tmpl
index a96e5c9367..4cfdbac73f 100644
--- a/templates/admin/navbar.tmpl
+++ b/templates/admin/navbar.tmpl
@@ -4,35 +4,60 @@
 		<a class="{{if .PageIsAdminDashboard}}active {{end}}item" href="{{AppSubUrl}}/admin">
 			{{.locale.Tr "admin.dashboard"}}
 		</a>
-		<a class="{{if .PageIsAdminUsers}}active {{end}}item" href="{{AppSubUrl}}/admin/users">
-			{{.locale.Tr "admin.users"}}
-		</a>
-		<a class="{{if .PageIsAdminOrganizations}}active {{end}}item" href="{{AppSubUrl}}/admin/orgs">
-			{{.locale.Tr "admin.organizations"}}
-		</a>
-		<a class="{{if .PageIsAdminRepositories}}active {{end}}item" href="{{AppSubUrl}}/admin/repos">
-			{{.locale.Tr "admin.repositories"}}
-		</a>
-		{{if .EnablePackages}}
-			<a class="{{if .PageIsAdminPackages}}active {{end}}item" href="{{AppSubUrl}}/admin/packages">
-				{{.locale.Tr "packages.title"}}
-			</a>
-		{{end}}
-		{{if not DisableWebhooks}}
+		<details class="item toggleable-item" {{if or .PageIsAdminUsers .PageIsAdminEmails .PageIsAdminOrganizations .PageIsAdminAuthentications}}open{{end}}>
+			<summary>{{.locale.Tr "admin.identity_access"}}</summary>
+			<div class="menu">
+				<a class="{{if .PageIsAdminAuthentications}}active {{end}}item" href="{{AppSubUrl}}/admin/auths">
+					{{.locale.Tr "admin.authentication"}}
+				</a>
+				<a class="{{if .PageIsAdminOrganizations}}active {{end}}item" href="{{AppSubUrl}}/admin/orgs">
+					{{.locale.Tr "admin.organizations"}}
+				</a>
+				<a class="{{if .PageIsAdminUsers}}active {{end}}item" href="{{AppSubUrl}}/admin/users">
+					{{.locale.Tr "admin.users"}}
+				</a>
+				<a class="{{if .PageIsAdminEmails}}active {{end}}item" href="{{AppSubUrl}}/admin/emails">
+					{{.locale.Tr "admin.emails"}}
+				</a>
+			</div>
+		</details>
+		<details class="item toggleable-item" {{if or .PageIsAdminRepositories (and .EnablePackages .PageIsAdminPackages)}}open{{end}}>
+			<summary>{{.locale.Tr "admin.assets"}}</summary>
+			<div class="menu">
+				{{if .EnablePackages}}
+					<a class="{{if .PageIsAdminPackages}}active {{end}}item" href="{{AppSubUrl}}/admin/packages">
+						{{.locale.Tr "packages.title"}}
+					</a>
+				{{end}}
+				<a class="{{if .PageIsAdminRepositories}}active {{end}}item" href="{{AppSubUrl}}/admin/repos">
+					{{.locale.Tr "admin.repositories"}}
+				</a>
+			</div>
+		</details>
+		<!-- Webhooks and OAuth can be both disabled here, so add this if statement to display different ui -->
+		{{if and (not DisableWebhooks) .EnableOAuth2}}
+			<details class="item toggleable-item" {{if or .PageIsAdminDefaultHooks .PageIsAdminSystemHooks .PageIsAdminApplications}}open{{end}}>
+				<summary>{{.locale.Tr "admin.integrations"}}</summary>
+				<div class="menu">
+					<a class="{{if .PageIsAdminApplications}}active {{end}}item" href="{{AppSubUrl}}/admin/applications">
+						{{.locale.Tr "settings.applications"}}
+					</a>
+					<a class="{{if or .PageIsAdminDefaultHooks .PageIsAdminSystemHooks}}active {{end}}item" href="{{AppSubUrl}}/admin/hooks">
+						{{.locale.Tr "admin.hooks"}}
+					</a>
+				</div>
+			</details>
+		{{else}}
+			{{if not DisableWebhooks}}
 			<a class="{{if or .PageIsAdminDefaultHooks .PageIsAdminSystemHooks}}active {{end}}item" href="{{AppSubUrl}}/admin/hooks">
 				{{.locale.Tr "admin.hooks"}}
 			</a>
-		{{end}}
-		<a class="{{if .PageIsAdminAuthentications}}active {{end}}item" href="{{AppSubUrl}}/admin/auths">
-			{{.locale.Tr "admin.authentication"}}
-		</a>
-		<a class="{{if .PageIsAdminEmails}}active {{end}}item" href="{{AppSubUrl}}/admin/emails">
-			{{.locale.Tr "admin.emails"}}
-		</a>
-		{{if .EnableOAuth2}}
-			<a class="{{if .PageIsAdminApplications}}active {{end}}item" href="{{AppSubUrl}}/admin/applications">
-				{{.locale.Tr "settings.applications"}}
-			</a>
+			{{end}}
+			{{if .EnableOAuth2}}
+				<a class="{{if .PageIsAdminApplications}}active {{end}}item" href="{{AppSubUrl}}/admin/applications">
+					{{.locale.Tr "settings.applications"}}
+				</a>
+			{{end}}
 		{{end}}
 		{{if .EnableActions}}
 		<details class="item toggleable-item" {{if .PageIsSharedSettingsRunners}}open{{end}}>