Make exceptions part of the specification

[wwebers]

In JAX-RS exceptions and error handling is a substantial part of its specification. This enables the handling of exceptions possible on applicationlevel even in cases where exceptions are thrown outside without being forced to bind directly to the implementors exception classes.

This is because every implementor has to throw exceptions being instances of those standard WebApplicationException classes.

This is not the case for Microprofile JWT. If applications like to catch those implementors exceptions (smallrye for example), such applications have to realize a strong binding to exactly those implementors. This could be seen contraproductive to using standards, will say one would like to easily switch vendors/implementors of the Microprofile JWT specification.

Right now one has to to conclude: Microprofile JWT = smallrye

Proposal is going towards going the same route like JAX-RS. Same could be said för the remaining parts of Microprofile.