Add subsystem test with hierarchy of resources using expression resolution

This test will cover a few different perspectives:

1. A hierarchy of resources in the Elytron subsystem which require expression resolution or credentials from credential stores.
2. Management operations on the expression=encryption resource.
   1. Default and non-default expression resolver.
   2. Error handling where expression resolver references a key that does not exist.
3. Verify error handling regarding a cycle of resources.