Unfurl Support for Code Search in Advanced Search

Problem to solve

When pasting a URL of a Search Result page it gives little context to what is on the page linked.

Now more detailed information about the search result page will be displayed when you share links in applications like Slack.

Example

https://gitlab.com/search?group_id=4423825&project_id=8813524&repository_ref=&scope=blobs&search=key%22%3A&snippets=false

https://www.cnn.com/2014/01/06/tech/web/ces-unveiled/index.html?hpt=hp_c3

User experience goal

Update the Meta headers on the Advanced Global Search Result page to give a better description when links are posted in Apps like slack.

Further details

https://medium.com/slack-developer-blog/everything-you-ever-wanted-to-know-about-unfurling-but-were-afraid-to-ask-or-how-to-make-your-e64b4bb9254

This would Ideally not exceed the "classic Link Unfurling". https://api.slack.com/reference/messaging/link-unfurling#classic_unfurl

This will probably only work if the page is public.

Need to confirm our rules for Bots will allow it. https://api.slack.com/robots