New messaging activemq resources

[spriadka]

Added tests for the Remote ActiveMQ Server configuration in view + refactoring.

Upstream Issue: https://issues.jboss.org/browse/HAL-1528 EAP7 Issue: https://issues.jboss.org/browse/EAP7-1130

[spriadka]

• UI changes MessagingRemoteActiveMQPage
• Most important test code changes MessagingFixtures ConnectionFactoryTest GenericConnectorTest HttpConnectorTest InVMConnectorTest RemoteConnectorTest DiscoveryGroupTest ExternalJMSQueueTest ExternalJMSTopicTest PooledConnectionFactoryTest PooledConnectionFactory -> Attributes PooledConnectionFactory -> Credential Reference

[hpehl]

LGTM.