Add support for JSR 107 cache

[marcusdacoregio]

Since we will drop the EhCache2 support in 6.0, we should add support for JCache which EhCache3 is fully compliant

[rwinch]

What specific cache are you thinking? I wonder if we should or already have an implementation that uses Spring abstraction which has implementations for all sorts of caches?

[marcusdacoregio]

Thanks @rwinch, yes we do have the org.springframework.security.core.userdetails.cache.SpringCacheBasedUserCache that uses the Spring abstraction. I'll close this as invalid.