Add class to page content to unify top margin (#13766)

* Add class to page content to unify top margin

Previously pages would individually set this margin but some didn't so
content would stick to the header without any space. Resolve this by
adding a new class that is added on all pages. The only place where we
remove this margin again is on the pages with menu or wrapper in the
header.

* fix admin notices

* fix team pages

* fix loading segment on gitgraph for arc-green

* fix last missing case

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

templates/org/settings/delete.tmpl

@@ -1,5 +1,5 @@
 {{template "base/head" .}}
-<div class="organization settings delete">
+<div class="page-content organization settings delete">
 	{{template "org/header" .}}
 	<div class="ui container">
 		<div class="ui grid">

templates/org/settings/hook_new.tmpl

@@ -1,5 +1,5 @@
 {{template "base/head" .}}
-<div class="organization settings new webhook">
+<div class="page-content organization settings new webhook">
 	{{template "org/header" .}}
 	<div class="ui container">
 		<div class="ui grid">

templates/org/settings/hooks.tmpl

@@ -1,5 +1,5 @@
 {{template "base/head" .}}
-<div class="organization settings webhooks">
+<div class="page-content organization settings webhooks">
 	{{template "org/header" .}}
 	<div class="ui container">
 		<div class="ui grid">

templates/org/settings/labels.tmpl

@@ -1,5 +1,5 @@
 {{template "base/head" .}}
-<div class="organization settings labels">
+<div class="page-content organization settings labels">
 	{{template "org/header" .}}
 	<div class="ui container">
 		<div class="ui grid">

templates/org/settings/options.tmpl

@@ -1,5 +1,5 @@
 {{template "base/head" .}}
-<div class="organization settings options">
+<div class="page-content organization settings options">
 	{{template "org/header" .}}
 	<div class="ui container">
 		<div class="ui grid">