Make auth/authz API and components to be more generic

[artem-v]

Main issue - there's way too much coupling on Map<String, String>:

• io.scalecube.services.auth.CredentialsCodec
• io.scalecube.services.transport.api.ServiceTransport.CredentialsSupplier
• io.scalecube.services.auth.CredentialsSupplier
• io.scalecube.services.auth.Authenticator
• io.scalecube.services.transport.rsocket.ConnectionSetup#ConnectionSetup(java.util.Map<java.lang.String,java.lang.String>)
• io.scalecube.services.transport.rsocket.RSocketClientTransport#getCredentials
• io.scalecube.services.methods.ServiceMethodInvoker#authenticate

Intermediate auth/authz data must not be Map or List or something else, it must be abstract type T (or byte[]) and only edge components must declare how to interpret this type.

[artem-v]

Closing. Fixed at #903.