URL Namespacing

As a user of Workbench, I want to be able to configure a namespace for URLs:

• ATT&CK ID URLs. The ATT&CK ID object in the list of external references contains a URL that is currently hardcoded to attack.mitre.org. I would like to be able to configure this URL.
• LinkById tags. LinkById tags are parsed into a markdown link formatted as [Object Name](https://attack.mitre.org/type/object_id) when exporting objects & collections. I would like to be able to configure the URL for this markdown link, rather than use the hardcoded attack.mitre.org URL.
  • The specified URL should be used to convert LinkById tags to markdown links. For example, if the admin configures https://example.com/ as the URL, LinkById tags should be converted to [Object Name](https://example.com/type/object_id)
• The admin should be able to define an ATT&CK ID URL and/or LinkById URL on the organization settings page. If no URL is specified, default to attack.mitre.org

Start at the organization settings page and trace the export and LinkById parsing entry points described in the issue. Check how ATT&CK ID URLs and markdown links currently use the hardcoded host, then verify that configured URLs override it while the default remains attack.mitre.org.