Issue sidebar and misc css fixes (#15524)

- Replace remaining font icons with SVG in issue sidebar
- Rework issue due date display
- Realign avatar in timeline
- Fix font size in repo search and code explore
- Consolidate active button styles
- Fix loading form on arc-green
- Align time tracker buttons vertically

Fixes: https://github.com/go-gitea/gitea/issues/15896

templates/user/profile.tmpl

@@ -92,21 +92,27 @@
 					</a>
 					{{if not .DisableStars}}
 						<a class='{{if eq .TabName "stars"}}active{{end}} item' href="{{.Owner.HomeLink}}?tab=stars">
-							{{svg "octicon-star"}}  {{.i18n.Tr "user.starred"}}
-							<div class="ui label">{{.Owner.NumStars}}</div>
+							{{svg "octicon-star"}} {{.i18n.Tr "user.starred"}}
+							{{if .Owner.NumStars}}
+								<div class="ui primary label">{{.Owner.NumStars}}</div>
+							{{end}}
 						</a>
 					{{else}}
 						<a class='{{if eq .TabName "watching"}}active{{end}} item' href="{{.Owner.HomeLink}}?tab=watching">
-							{{svg "octicon-eye"}}  {{.i18n.Tr "user.watched"}}
+							{{svg "octicon-eye"}} {{.i18n.Tr "user.watched"}}
 						</a>
 					{{end}}
 					<a class='{{if eq .TabName "following"}}active{{end}} item' href="{{.Owner.HomeLink}}?tab=following">
-						{{svg "octicon-person"}}  {{.i18n.Tr "user.following"}}
-						<div class="ui label">{{.Owner.NumFollowing}}</div>
+						{{svg "octicon-person"}} {{.i18n.Tr "user.following"}}
+						{{if .Owner.NumFollowing}}
+							<div class="ui primary label">{{.Owner.NumFollowing}}</div>
+						{{end}}
 					</a>
 					<a class='{{if eq .TabName "followers"}}active{{end}} item' href="{{.Owner.HomeLink}}?tab=followers">
-						{{svg "octicon-person"}}  {{.i18n.Tr "user.followers"}}
-						<div class="ui label">{{.Owner.NumFollowers}}</div>
+						{{svg "octicon-person"}} {{.i18n.Tr "user.followers"}}
+						{{if .Owner.NumFollowers}}
+							<div class="ui primary label">{{.Owner.NumFollowers}}</div>
+						{{end}}
 					</a>
 				</div>