ISIS-537: pattern matching of CSS classes based on action name (similar to FA icons)

Also: required to inject ServicesInjector into facet factory to query whether a method was from a service or not.  To support this, refactored so that ServicesInjectorDefault is basically has global scope as opposed to session/request scope.  Implementation adapted from that already used for SpecificationLoader (aka the ObjectReflector).  A bit hacky, but a move in the right general direction.
ISIS-537: refactored EntityHeaderPanel to use additional links instead of CssMenuBuilder.
ISIS-537: deleting the defunct parts of CssMenu panel and items etc
ISIS-537: further deletion of unused CssMenuItem stuff.
ISIS-537: fixing up ServicesInjectorDefault initialization, responsibility for instantiation now solely in PersistenceSessionFactory, and ObjectReflectorDefault (SpecficationLoaderSpi) is handed a copy rather than instantiate its own instance.

There's plenty of scope to improve matters further, but the test that was failing is at least now passing.