By default force vertical tabs on mobile (#19486)

* By default force vertical tabs on mobile

- While experimenting with using vertical tabs instead of horizontal
tabs on gitea for a better mobile experience, I made a recent
PR(https://github.com/go-gitea/gitea/pull/19468) in order to see if
there was any objections to this new behavior for the repo headers(one
of the most annoying horizontal tabs). This PR had no objections and
even a user commenting that this change is brilliant.
- This PR now improves upon the previous PR by making this the de-facto
behavior for all menu's on mobile. The only exemption is the navbar
which also uses the menu but caught some layout errors with the changes.

* Fix organisation

* Fix repo/wiki buttons

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

templates/repo/home.tmpl

@@ -60,7 +60,7 @@
 			</div>
 		{{end}}
 		{{template "repo/sub_menu" .}}
-		<div class="ui stackable secondary menu mobile--margin-between-items mobile--no-negative-margins">
+		<div class="ui stackable secondary menu mobile--margin-between-items mobile--no-negative-margins no-vertical-tabs">
 			{{template "repo/branch_dropdown" dict "root" .}}
 			{{ $n := len .TreeNames}}
 			{{ $l := Subtract $n 1}}