Add <overflow-menu>, rename webcomponents (#29400)

1. Add `<overflow-menu>` web component
2. Rename `<gitea-origin-url>` to `<origin-url>` and make filenames
match.

<img width="439" alt="image"
src="https://github.com/go-gitea/gitea/assets/115237/2fbe4ca4-110b-4ad2-8e17-c1e116ccbd74">

<img width="444" alt="Screenshot 2024-03-02 at 21 36 52"
src="https://github.com/go-gitea/gitea/assets/115237/aa8f786e-dc8c-4030-b12d-7cfb74bdfd6e">

<img width="537" alt="Screenshot 2024-03-03 at 03 05 06"
src="https://github.com/go-gitea/gitea/assets/115237/fddd50aa-adf1-4b4b-bd7f-caf30c7b2245">


![image](https://github.com/go-gitea/gitea/assets/115237/0f43770c-834c-4a05-8e3d-d30eb8653786)


![image](https://github.com/go-gitea/gitea/assets/115237/4b4c6bd7-843f-4f49-808f-6b3aed5e9f9a)

TODO:

- [x] Check if removal of `requestAnimationFrame` is possible to avoid
flash of content. Likely needs a `MutationObserver`.
- [x] Hide tippy when button is removed from DOM.
- [x] ~~Implement right-aligned items
(https://github.com/go-gitea/gitea/pull/28976)~~. Not going to do it.
- [x] Clean up CSS so base element has no background and add background
via tailwind instead.
- [x] Use it for org and user page.

---------

Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/repo/header.tmpl

@@ -126,9 +126,9 @@
 		{{if .IsGenerated}}<div class="fork-flag">{{ctx.Locale.Tr "repo.generated_from"}} <a href="{{(.TemplateRepo ctx).Link}}">{{(.TemplateRepo ctx).FullName}}</a></div>{{end}}
 	</div>
 {{end}}
-	<div class="ui container secondary pointing tabular top attached borderless menu new-menu navbar">
+	<overflow-menu class="ui container secondary pointing tabular top attached borderless menu navbar tw-pt-0 tw-my-0">
 		{{if not (or .Repository.IsBeingCreated .Repository.IsBroken)}}
-			<div class="new-menu-inner">
+			<div class="overflow-menu-items">
 				{{if .Permission.CanRead $.UnitTypeCode}}
 				<a class="{{if .PageIsViewCode}}active {{end}}item" href="{{.RepoLink}}{{if and (ne .BranchName .Repository.DefaultBranch) (not $.PageIsWiki)}}/src/{{.BranchNameSubURL}}{{end}}">
 					{{svg "octicon-code"}} {{ctx.Locale.Tr "repo.code"}}
@@ -220,12 +220,12 @@
 				{{end}}
 			</div>
 		{{else if .Permission.IsAdmin}}
-			<div class="new-menu-inner">
+			<div class="overflow-menu-items">
 				<a class="{{if .PageIsRepoSettings}}active {{end}} item" href="{{.RepoLink}}/settings">
 					{{svg "octicon-tools"}} {{ctx.Locale.Tr "repo.settings"}}
 				</a>
 			</div>
 		{{end}}
-	</div>
+	</overflow-menu>
 	<div class="ui tabs divider"></div>
 </div>