Work around fomantic 2.8.5 bugs (#11767)

Work around fomantic 2.8.5 bugs 

Closes #11759

Related fomantic/Fomantic-UI#1372 and fomantic/Fomantic-UI#1473

templates/repo/issue/view_content/pull.tmpl

@@ -283,7 +283,7 @@
 								</button>
 								<div class="ui dropdown icon button">
 									<i class="dropdown icon"></i>
-									<div class="menu">
+									<div class="menu left">
 										{{if $prUnit.PullRequestsConfig.AllowMerge}}
 										<div class="item{{if eq .MergeStyle "merge"}} active selected{{end}}" data-do="merge">{{$.i18n.Tr "repo.pulls.merge_pull_request"}}</div>
 										{{end}}

web_src/less/_base.less

@@ -1048,6 +1048,14 @@ i.icon.centerlock {
     top: 1.45em;
 }
 
+// temporary workaround for fomantic 2.8.5 bug
+// https://github.com/go-gitea/gitea/pull/11767
+i.icon,
+i.icons {
+    vertical-align: unset;
+    line-height: unset;
+}
+
 .ui.label {
     padding: .3em .5em;
 }