Use template context function for avatar rendering (#26385)

Introduce `AvatarUtils`, no need to pass `$.Context` to every
sub-template, and simplify the template helper functions.

templates/shared/issuelist.tmpl

@@ -37,7 +37,7 @@
 						<div class="text grey">
 							{{range .Assignees}}
 								<a class="ui assignee gt-no-underline" href="{{.HomeLink}}" data-tooltip-content="{{.GetDisplayName}}">
-									{{avatar $.Context . 20}}
+									{{ctx.AvatarUtils.Avatar . 20}}
 								</a>
 							{{end}}
 						</div>

templates/shared/user/avatarlink.tmpl

@@ -1 +1 @@
-<a class="avatar"{{if gt .user.ID 0}} href="{{.user.HomeLink}}"{{end}}>{{avatar $.Context .user}}</a>
+<a class="avatar"{{if gt .user.ID 0}} href="{{.user.HomeLink}}"{{end}}>{{ctx.AvatarUtils.Avatar .user}}</a>

templates/shared/user/org_profile_avatar.tmpl

@@ -3,7 +3,7 @@
 		<div class="ui vertically grid head">
 			<div class="column">
 				<div class="ui header">
-					{{avatar $.Context . 100}}
+					{{ctx.AvatarUtils.Avatar . 100}}
 					<span class="text thin grey"><a href="{{.HomeLink}}">{{.DisplayName}}</a></span>
 					<span class="org-visibility">
 						{{if .Visibility.IsLimited}}<div class="ui medium basic horizontal label">{{$.locale.Tr "org.settings.visibility.limited_shortname"}}</div>{{end}}

templates/shared/user/profile_big_avatar.tmpl

@@ -3,11 +3,11 @@
 	{{if eq .SignedUserID .ContextUser.ID}}
 		<a class="image" href="{{AppSubUrl}}/user/settings" data-tooltip-content="{{.locale.Tr "user.change_avatar"}}">
 			{{/* the size doesn't take affect (and no need to take affect), image size(width) should be controlled by the parent container since this is not a flex layout*/}}
-			{{avatar $.Context .ContextUser 256}}
+			{{ctx.AvatarUtils.Avatar .ContextUser 256}}
 		</a>
 	{{else}}
 		<span class="image">
-			{{avatar $.Context .ContextUser 256}}
+			{{ctx.AvatarUtils.Avatar .ContextUser 256}}
 		</span>
 	{{end}}
 	</div>
@@ -86,7 +86,7 @@
 					{{if (or .Visibility.IsPublic (and ($.SignedUser) (or .Visibility.IsLimited (and (.HasMemberWithUserID $.SignedUserID) .Visibility.IsPrivate) ($.IsAdmin))))}}
 					<li>
 						<a href="{{.HomeLink}}" data-tooltip-content="{{.Name}}">
-							{{avatar $.Context .}}
+							{{ctx.AvatarUtils.Avatar .}}
 						</a>
 					</li>
 					{{end}}