Add No Results Prompt Message on Issue List Page (go-gitea#33699)

(cherry picked from commit 2cd2ae0)

Author: kerwin612

options/locale/locale_en-US.ini

@@ -1540,6 +1540,8 @@ issues.filter_milestones = Filter Milestone
 issues.filter_projects = Filter Project
 issues.filter_labels = Filter Label
 issues.filter_reviewers = Filter Reviewer
+issues.filter_no_results = No results
+issues.filter_no_results_placeholder = Try adjusting your search filters.
 issues.new = New issue
 issues.new.title_empty = Title cannot be empty
 issues.new.labels = Labels
@@ -3963,4 +3965,4 @@ filepreview.lines = Lines %[1]d to %[2]d in %[3]s
 filepreview.truncated = Preview has been truncated
 
 [translation_meta]
-test = This is a test string. It is not displayed in Forgejo UI but is used for testing purposes. Feel free to enter "ok" to save time (or a fun fact of your choice) to hit that sweet 100% completion mark :)
+test = This is a test string. It is not displayed in Forgejo UI but is used for testing purposes. Feel free to enter "ok" to save time (or a fun fact of your choice) to hit that sweet 100% completion mark :)

templates/shared/issuelist.tmpl

@@ -145,6 +145,11 @@
 				</div>
 			</div>
 		</div>
+	{{else}}
+		<div class="tw-text-center tw-p-8">
+			<h3 class="tw-my-4">{{ctx.Locale.Tr "repo.issues.filter_no_results"}}</h3>
+			<p class="tw-text-placeholder-text">{{ctx.Locale.Tr "repo.issues.filter_no_results_placeholder"}}</p>
+		</div>
 	{{end}}
 	{{if .IssueIndexerUnavailable}}
 		<div class="ui error message">