HTML: Add error message to "search issues on GitHub" link (#4652)

This PR adds the error message to the "search on Github" link located on
the crash page, so that the search bar is already filled and the issues
filtered when the user opens said link.

As seen with #4584 and other critical problems, duplicate issues end up
unnecessarily flooding the issue reports. While this change won't entirely
stop this behavior, this will help the user to easily identify if the error
they have received has been reported yet and discourage them from creating
a duplicate (hopefully...).

No associated issue was open

src/invidious/helpers/errors.cr

@@ -43,6 +43,8 @@ def error_template_helper(env : HTTP::Server::Context, status_code : Int32, exce
   # URLs for the error message below
   url_faq = "https://github.com/iv-org/documentation/blob/master/docs/faq.md"
   url_search_issues = "https://github.com/iv-org/invidious/issues"
+  url_search_issues += "?q=is:issue+is:open+"
+  url_search_issues += URI.encode_www_form("[Bug] #{issue_title}")
 
   url_switch = "https://redirect.invidious.io" + env.request.resource