refactor: clean up pull request comment related code and template dict (#39789)

1. drop comment.commit_id
2. refactor templates, remove `dict "." .` from templates

templates/shared/search/code/results.tmpl

@@ -29,7 +29,7 @@
 			<div class="ui attached table segment">
 				{{template "shared/searchfile" dict "RepoLink" $repo.Link "SearchResult" .}}
 			</div>
-			{{template "shared/searchbottom" dict "root" $ "result" .}}
+			{{template "shared/searchbottom" dict "result" .}}
 		</div>
 	{{end}}
 </div>