[Feature Request] Remove M.IM.Tokens.Experimental namespace.

[brentschmaltz]

We have a new model for validating tokens without throwing exceptions which results in a reduced memory footprint and improved latency.

Currently we have most of the code in M.IM.Tokens.Experimental namespace.
Removing this namespace will be a breaking change.

We will need to bump the major version before we do this.
We would like for the methods on IResultBasedValidation to be available for all TokenHandlers.
Currently IResultBasedValidation was added to JsonWebTokenHandler, SamlSecurityTokenHandler and Saml2SecurityTokenHandler.
Which implies an opt in model on a TokenHandler basis, which results in the need for logic based on type.

To resolve this:

1. IResultBasedValidation methods could be added to M.IM.Tokens.TokenHandler.
2. IResultBasedValidation could be added as an interface to M.IM.Tokens.TokenHandler.

The result should be that any runtime working with a TokenHandler should be able to call the new methods.