[3.9.1] Deferred/Sensitive not woking for docker::registry

When using the Deferred function of puppet it will fails on docker::registry.
Sample code:

docker::registry { 'foo':
  username => Deferred(foo_function, [foo_option]),
  password  =>  Deferred(foo_function, [foo_option]),
}

will fails with:

parameter 'username' expects a value of type Undef or String, got Deferred
parameter 'password' expects a value of type Undef or String, got Deferred

The same will happens when using Sensitive(Deferred(..))

 parameter 'username' expects a value of type Undef or String, got Sensitive[Deferred]
  parameter 'password' expects a value of type Undef or String, got Sensitive[Deferred]

Start at the docker::registry resource and reproduce the reported Deferred and Sensitive(Deferred) examples. Review linked pull request #1066 for the work already underway; the issue is done when both username and password accept these values without the shown type errors.