feat: implement oauth2 client credentials auth profile

[ndr-brt]

What

Implements oauth2 client credentials auth profile

How

By registering the authorization profile on the Dataplane instance:

Dataplane.newInstance()
    .registerAuthorization(new Oauth2ClientCredentialsAuthorization())
    ...
    .build()

And registering the control-plane with such profile, every call made to that control-plane will be done by requesting a new jwt token to the configured tokenUrl with clientId and clientSecret attributes.

NOTE: this is not much more than an example, a more fine tuned implementation with token caching and refresh would be up to the user.

Additional notest

• refactored a little to make the AuthorizationProfile usage easier and less convoluted

Closes #42

[ronjaquensel]

🚀