[FIX] website: better match local anchor links

When a menu link is defined towards an anchor, the scroll effect of the
browser does not trigger from within the translated pages where the URL
contains the additional path element about the used locale.

The language is added in `ir.http`'s `url_lang` method, but we cannot
always know the current URL at that point, nor during the template
rendering - making it impossible to determine if the rendered anchor
is local.

This commit solves this client-side by first uniformizing the current
and the target pathnames so that they both end with a `/`, and then, if
they match replacing the link's target pathname by the window pathname
so that the browser sees them as the same page.

Steps to reproduce:
- Install `website`.
- Install a second language on the website.
- Put some content in the Home page so that the bottom section requires
scrolling to be seen.
- Add a menu element that targets `#bottom`.
- Either be a visitor or a connected user.
- Go to the default language Home page.
- Click on the new link. => Page scrolls to the bottom.
- Switch to the second language Home page.
- Click on the new link.

=> Page reloads targeting the bottom instead of scrolling.

In master, remove `scroller_service.js` from `web`'s manifest.

opw-3956066

closes #169944

Signed-off-by: Benjamin Vray (bvr) <bvr@odoo.com>

addons/website/static/src/js/content/snippets.animation.js

@@ -1065,9 +1065,14 @@ registry.anchorSlide = publicWidget.Widget.extend({
      * @private
      */
     _onAnimateClick: function (ev) {
-        if (this.$target[0].pathname !== window.location.pathname) {
+        const ensureSlash = path => path.endsWith("/") ? path : path + "/";
+        if (ensureSlash(this.$target[0].pathname) !== ensureSlash(window.location.pathname)) {
             return;
         }
+        // Avoid flicker at destination in case of ending "/" difference.
+        if (this.$target[0].pathname !== window.location.pathname) {
+            this.$target[0].pathname = window.location.pathname;
+        }
         var hash = this.$target[0].hash;
         if (hash === '#top' || hash === '#bottom') {
             // If the anchor targets #top or #bottom, directly call the