Refactor, again

Make collapsible components reusable
Add ability to collapse video rows in videos-grid style
Lose sanity while dealing with all the intricacies

internal/assets/templates/rss-list.html

@@ -1,7 +1,7 @@
 {{ template "widget-base.html" . }}
 
 {{ define "widget-content" }}
-<ul class="list list-gap-14 list-collapsible" data-collapse-after="{{ .CollapseAfter }}">
+<ul class="list list-gap-14 collapsible-container" data-collapse-after="{{ .CollapseAfter }}">
     {{ range .Items }}
     <li>
         <a class="size-title-dynamic color-primary-if-not-visited" href="{{ .Link }}" target="_blank" rel="noreferrer">{{ .Title }}</a>