FEATURE: add override for crawler title and description tags (#32259)

In https://github.com/discourse/discourse/pull/32159 we overrode the
`og:` and `twitter:` title and description but for some crawlers, we
need to override the `title` and `description` meta tag as well.

app/helpers/application_helper.rb

@@ -270,6 +270,24 @@ module ApplicationHelper
     (request ? I18n.locale.to_s : SiteSetting.default_locale).sub("_", "-")
   end
 
+  def crawlable_title_content
+    DiscoursePluginRegistry.apply_modifier(
+      :meta_data_content,
+      content_for(:title) || SiteSetting.title,
+      :title,
+      { url: request.fullpath },
+    )
+  end
+
+  def crawlable_description_content
+    DiscoursePluginRegistry.apply_modifier(
+      :meta_data_content,
+      @description_meta || SiteSetting.site_description,
+      :description,
+      { url: request.fullpath },
+    )
+  end
+
   # Creates open graph and twitter card meta data
   def crawlable_meta_data(opts = nil)
     opts ||= {}