[Broker-J][AMQP 1.0][Tests] Improve protocol tests to be able to run the test suite against external broker

The existing protocol test framework allows to run test against external broker only when annotation RunBrokerAdmin is added to the test class with a type pointing to external broker admin type.

With this approach the implemented test can only be executed with a particular broker admin type.

The original intention of protocol tests was to allow running protocol tests against any AMQP compliment broker. The specific broker admin needs to be injected into the test framework.

Currently, we have "external" and "embedded" broker admin type, but, there is no way to execute protocol tests even against external Qpid broker.

We need to modify protocol test framework to allow running existing tests against external broker