Create the 'yiisoft/auth-session' package to replace the 'yiisoft/user' package

[klsoft-web]

The 'user' term is more relevant to a package that implements the Yiisoft\Auth\IdentityInterface interface, whereas the yiisoft/user package implements various authentication methods via the session:

• The authenticate(ServerRequestInterface $request) method checks if an identity ID is saved in the session.
• The login(IdentityInterface $identity) method sets an identity ID in the session.
• The logout() method removes an identity ID from the session.
  And so on.

The names 'ApiAuth' and 'WebAuth' do not have to be related to the API or web application.
The AuthenticatorInterface is a universal interface for any application that uses sessions.

As the 'yiisoft/user' package contains many misleading names, including its own, the following names were suggested for the new package:

• 'yiisoft/auth-session' instead of 'yiisoft/user'
• AuthManager instead of CurrentUser
• Authenticator instead of ApiAuth and WebAuth

The AuthManager method names are:

• isAuthenticated() instead of isGuest()