[Licensing] Check is License Management is enabled when linking to it

[yuliacech]

The Licensing plugin has a banner for expired license that links to the License Management plugin. If the License Management plugin is disabled, this link might lead to a Not Found route in Kibana in that case. We can't make the Licensing plugin be dependant on the License Management because there is already a dependency the other way around.

[elasticmachine]

Pinging @elastic/platform-deployment-management (Team:Deployment Management)

[alisonelizabeth]

I think we can close this one, once #160671 is merged, as License Management will only be able to be disabled in serverless.

[alisonelizabeth]

Closing now that #160671 has been merged