Improve notifications, fix styles not being added

Based on https://petr.codes/blog/rails/modern-rails-flash-messages/part-3/

app/components/notification_component.rb

@@ -1,13 +1,22 @@
 # frozen_string_literal: true
 
+# @param type [String] Classic notification type `error`, `alert` and `info` + custom `success`
+# @param data [String, Hash] `String` for backward compatibility,
+#   `Hash` for the new functionality `{title: '', body: '', timeout: 5, countdown: false, action: { url: '', method: '', name: ''}}`.
+#   The `title` attribute for `Hash` is mandatory.
 class NotificationComponent < ViewComponent::Base
   def initialize(type:, data:)
     @type = type
     @data = prepare_data(data)
     @icon_name = icon_name
     @icon_color_class = icon_color_class
+
+    @data[:timeout] ||= 5
+    @data[:action][:method] ||= "get" if @data[:action]
   end
 
+  private
+
   def prepare_data(data)
     case data
     when Hash