Refactor htmx and fetch-action related code (#37186)

This is the first step (the hardest part):

* repo file list last commit message lazy load
* admin server status monitor
* watch/unwatch (normal page, watchers page)
* star/unstar (normal page, watchers page)
* project view, delete column
* workflow dispatch, switch the branch
* commit page: load branches and tags referencing this commit

The legacy "data-redirect" attribute is removed, it only makes the page
reload (sometimes using an incorrect link).

Also did cleanup for some devtest pages.

templates/admin/notice.tmpl

@@ -50,7 +50,7 @@
 										</div>
 									</div>
 								</div>
-								<button class="ui small button" id="delete-selection" data-link="{{.Link}}/delete" data-redirect="?page={{.Page.Paginater.Current}}">
+								<button class="ui small button" id="delete-selection" data-link="{{.Link}}/delete">
 									<span class="text">{{ctx.Locale.Tr "admin.notices.delete_selected"}}</span>
 								</button>
 							</th>