[ML] Await for license info in ML shared services

[darnautov]

The server-side components of ML shared services exposed through the contract setup, rely on the license and capabilities check, such as isFullLicense.

During the Kibana setup, if a plugin attempts to utilize any of these shared methods, will encounter an error because the licensing plugin hasn't been initialized yet. To enhance the experience of consuming ML-shared services, we should first ensure that the license plugin is ready before allowing access to these methods.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)