Align dropdown right (#14406)

templates/repo/issue/view_content/add_reaction.tmpl

@@ -1,5 +1,5 @@
 {{if .ctx.IsSigned}}
-<div class="item action ui pointing select-reaction dropdown" data-action-url="{{ .ActionURL }}">
+<div class="item action ui pointing select-reaction dropdown top right" data-action-url="{{ .ActionURL }}">
 	<a class="add-reaction">
 		{{svg "octicon-smiley"}}
 	</a>

templates/repo/issue/view_content/context_menu.tmpl

@@ -1,5 +1,5 @@
 {{if .ctx.IsSigned}}
-<div class="item action ui pointing custom dropdown context-dropdown">
+<div class="item action ui pointing custom dropdown top right context-dropdown">
 	<a class="context-menu">
 		{{svg "octicon-kebab-horizontal"}}
 	</a>

web_src/less/_base.less

@@ -1784,7 +1784,7 @@ a.ui.basic.label:hover {
 }
 
 /* fix misaligned right buttons on box headers */
-.ui.attached.header .right {
+.ui.attached.header .right:not(.dropdown) {
   position: absolute;
   right: .78571429rem;
   top: 0;