Fix link/origin referrer and login redirect (#36279)

Fix #35998

1. Fix `<a rel>` :
    * "_blank" already means "noopener"
* "noreferrer" is already provided by page's `<meta name="referrer">`
2. Fix "redirect_to" mechisam
* Use "referer" header to determine the redirect link for a successful
login
3. Simplify code and merge duplicate logic

templates/shared/user/profile_big_avatar.tmpl

@@ -38,7 +38,7 @@
 					{{svg "octicon-location"}}
 					<span class="tw-flex-1">{{.ContextUser.Location}}</span>
 					{{if .ContextUserLocationMapURL}}
-						<a href="{{.ContextUserLocationMapURL}}" rel="nofollow noreferrer" data-tooltip-content="{{ctx.Locale.Tr "user.show_on_map"}}">
+						<a href="{{.ContextUserLocationMapURL}}" data-tooltip-content="{{ctx.Locale.Tr "user.show_on_map"}}">
 							{{svg "octicon-link-external"}}
 						</a>
 					{{end}}
@@ -63,7 +63,7 @@
 			{{if .ContextUser.Website}}
 				<li>
 					{{svg "octicon-link"}}
-					<a target="_blank" rel="noopener noreferrer me" href="{{.ContextUser.Website}}">{{.ContextUser.Website}}</a>
+					<a target="_blank" rel="me" href="{{.ContextUser.Website}}">{{.ContextUser.Website}}</a>
 				</li>
 			{{end}}
 			{{if $.RenderedDescription}}
@@ -75,7 +75,7 @@
 				{{if .Show}}
 					<li>
 						{{svg "fontawesome-openid"}}
-						<a target="_blank" rel="noopener noreferrer" href="{{.URI}}">{{.URI}}</a>
+						<a target="_blank" href="{{.URI}}">{{.URI}}</a>
 					</li>
 				{{end}}
 			{{end}}