Split the implementation module into common, jwt-auth, jwt-build

[sberyozkin]

This PR simply splits the current implementation module as per the smallry forum discussion, 3 modules are introduced:

• common (smallrye-jwt-common artifact id) module: where KeyUtils and ResourceUtils utility code has been moved to

• jwt-build (smallrye-jwt-build artifact id) module: where the JWT build related code has been moved to

• jwt-auth module: the current implementation module - except that the utility and build code is now coming from smallrye-jwt-commonand smallrye-jwt-build; I think we can drop the smallrye-jwt-build dependency for 3.0.0 and let users who need it include it.

• KeyUtils and ResourceUtils are in io.smallrye.jwt package on master and in io.smallrye.jwt.util package in common so I've kept the original classes in jwt-auth for now but deprecated them and updated to delegate to their common friends. These jwt-auth deprecated classes can be dropped in 3.0.0

This is really it - plus some minor dependency clean-up made possible by this split.

After this PR is reviewed/merged I will follow up with 2 small fixes (#327, #321) and release 2.4.0

[MikeEdgar]

Looks good, I didn't notice anything outside the described changes.

[radcortez]

LGTM

[sberyozkin]

@MikeEdgar @radcortez thanks, that should improve the modularization picture; for 3.0.0 I'll propose adding jwt-jaxrs and move the jaxrs specific code into it - right now, for example, in Quarkus we do not use the JAX-RS classes

[sberyozkin]

@MikeEdgar by the way, I meant to invite you to MP JWT gitter channel but ended up adding you, I thought it would send an invitation but looks like you are already in that room :-), sorry about me somehow skipping the invitation step; please don't hesitate to pause the memebership :-) of that room/channel if it becomes too noisy - don't think it will be noisy there though... thanks

[MikeEdgar]

@sberyozkin - no problem. I realize now that I have not been getting notifications for that particular channel. I'll need to look into that :-)