Replace CSRF cookie with CrossOriginProtection (#36183)

Removes the CSRF cookie in favor of
[`CrossOriginProtection`](https://pkg.go.dev/net/http#CrossOriginProtection)
which relies purely on HTTP headers.

Fixes: https://github.com/go-gitea/gitea/issues/11188
Fixes: https://github.com/go-gitea/gitea/issues/30333
Helps: https://github.com/go-gitea/gitea/issues/35107

TODOs:

- [x] Fix tests
- [ ] Ideally add tests to validates the protection

---------

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

templates/repo/wiki/new.tmpl

@@ -10,7 +10,6 @@
 			{{end}}
 		</div>
 		<form class="ui form" action="?action={{if .PageIsWikiEdit}}_edit{{else}}_new{{end}}" method="post">
-			{{.CsrfTokenHtml}}
 			<div class="field {{if .Err_Title}}error{{end}}">
 				<input name="title" value="{{.title}}" aria-label="{{ctx.Locale.Tr "repo.wiki.page_title"}}" placeholder="{{ctx.Locale.Tr "repo.wiki.page_title"}}" autofocus required>
 			</div>