Refactor html templates

This commit entirely refactors the use of html templates. Instead of
inheriting from a shared template, we insert the results into a base
template.

internal/dis/component/server/templating/templating.go

@@ -0,0 +1,21 @@
+package templating
+
+import (
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
+)
+
+// Templating implements templating customization
+type Templating struct {
+	component.Base
+	Dependencies struct {
+		Routeables []component.Routeable
+		Menuable   []component.Menuable
+	}
+	menu lazy.Lazy[[]component.MenuItem]
+}
+
+var (
+	_ component.Backupable = (*Templating)(nil)
+	_ component.Menuable   = (*Templating)(nil)
+)