Deprecate Infinispan container/cache start mode

start="EAGER" was only added to the Infinispan subsystem for use by JDG - so that a given container or cache service would install as ACTIVE rather than ON_DEMAND. In the context of WildFly, we would never want this since the modules referenced by cache entries may not yet be loaded. Many users configure start="EAGER" and inevitably have issues during redeploy. Consequently, we should drop this from the subsystem XSD altogether and deprecate it from the model.
Effectively, only start="LAZY" will be supported.