ISPN-3950 Allow deployment of event filters and converters in server

https://issues.jboss.org/browse/ISPN-3950

A long awaited PR completing functionality in Hot Rod event (barring some small fixes) by allowing filter and converter instances to be deployed in Infinispan Servers. Adding filters and converters is a dynamic process now to make it easier to fit into the deployment model.

This PR also includes refactoring of filter and converter factory classes to `core` module, as agreed on a dev discussion.
If you have multiple endpoints enabled, this fails with 
java.lang.IllegalStateException: JBAS018786: Multiple deployment unit processors registered with priority 6145 and class class org.infinispan.server.endpoint.deployments.FilterFactoryExtensionProcessor
So probably the deployer should be installed independently and added as a dependency.