Show total TrackedTime on issue/pull/milestone lists (#26672)

TODOs:
- [x] write test for `GetIssueTotalTrackedTime`
- [x] frontport kitharas template changes and make them mobile-friendly

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![image](https://github.com/go-gitea/gitea/assets/24977596/6713da97-201f-4217-8588-4c4cec157171)

![image](https://github.com/go-gitea/gitea/assets/24977596/3a45aba8-26b5-4e6a-b97d-68bfc2bf9024)

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*Sponsored by Kithara Software GmbH*

templates/repo/issue/filters.tmpl

@@ -4,6 +4,15 @@
 			<input type="checkbox" autocomplete="off" class="issue-checkbox-all gt-mr-4" title="{{ctx.Locale.Tr "repo.issues.action_check_all"}}">
 		{{end}}
 		{{template "repo/issue/openclose" .}}
+		<!-- Total Tracked Time -->
+		{{if .TotalTrackedTime}}
+			<div class="ui compact tiny secondary menu">
+				<span class="item" data-tooltip-content='{{ctx.Locale.Tr "tracked_time_summary"}}'>
+					{{svg "octicon-clock"}}
+					{{.TotalTrackedTime | Sec2Time}}
+				</span>
+			</div>
+		{{end}}
 	</div>
 	<div class="issue-list-toolbar-right">
 		<div class="ui secondary filter menu labels">

templates/repo/issue/list.tmpl

@@ -34,6 +34,15 @@
 		<div id="issue-actions" class="issue-list-toolbar gt-hidden">
 			<div class="issue-list-toolbar-left">
 				{{template "repo/issue/openclose" .}}
+				<!-- Total Tracked Time -->
+				{{if .TotalTrackedTime}}
+					<div class="ui compact tiny secondary menu">
+						<span class="item" data-tooltip-content='{{ctx.Locale.Tr "tracked_time_summary"}}'>
+							{{svg "octicon-clock"}}
+							{{.TotalTrackedTime | Sec2Time}}
+						</span>
+					</div>
+				{{end}}
 			</div>
 			<div class="issue-list-toolbar-right">
 				{{template "repo/issue/filter_actions" .}}

templates/repo/issue/milestone_issues.tmpl

@@ -46,6 +46,12 @@
 					{{end}}
 				</div>
 				<div class="gt-mr-3">{{ctx.Locale.Tr "repo.milestones.completeness" .Milestone.Completeness | Safe}}</div>
+				{{if .TotalTrackedTime}}
+					<div data-tooltip-content='{{ctx.Locale.Tr "tracked_time_summary"}}'>
+						{{svg "octicon-clock"}}
+						{{.TotalTrackedTime | Sec2Time}}
+					</div>
+				{{end}}
 			</div>
 		</div>
 		<div class="divider"></div>