Road to version 2 - Refactor and rewrite most of the library

Created by: drupol

This PR

• This will be the future version of cas-lib (version 2)
• Break backward compatibility
• Make sure that the CAS service is stateless by avoiding injecting the $request in the CAS constructor, also make sure that the Request is passed to each relevant method instead of being injected in the constructor.
• Make it PSR15 compatible
• Simplify configuration, get rid of allowed_parameters property.
• Merge handlers, services and redirect classes.
• Remove the dependency to monolog/monolog and throw exceptions when needed.
• Remove Introspector, use Response decorator and factories
• Now depends on loophp/psr17
• Has more and updated tests

Related to https://github.com/ecphp/cas-bundle/issues/63 and https://github.com/ecphp/cas-bundle/pull/59 Related to https://github.com/ecphp/ecas/pull/27 Related to https://github.com/ecphp/eu-login-bundle/pull/40