Add configuration for External URL for Lidarr

[Isaacntk]

Hi,

Right now when you click on "View in Lidarr" on an album, it uses the Lidarr URL that was configured at installation.

In a docker installation, or if both Lidarr and Aurral are installed behind a reverse proxy, clicking on this would take you to an inaccessible URL.

For example if Lidarr URL is set to http://lidarr:8686 for a docker installation, Aurral would be able to resolve the URL but no web browser would be able to resolve that internal docker address.

Would request for a new field to be added to allow external URLs to be set, which would just influence the links generated on the "View in Lidarr" button

Thanks!