ISPN-3163 Version generation should be common for all use cases

* By doing this, compatibility mode updates will result in change of
version which helps keep the premise that when data changes, version
changes too. This is needed for Hot Rod and Memcached endpoints.
* Version generator is therefor now a component that can be used by
server endpoints to generate version information.
* ClusterIdGenerator dissapears as a result of this and instead a
VersionGenerator class has been created that does the same job.