remove old bs to kafka, forwarder

[rerpha]

This will be deployed separately to IBEX and we have gained some knowledge of the forwarder from doing this such as the issue with gateway changes causing disconnects.

bskafka is now https://github.com/ISISComputingGroup/kafka_forwarder_configurer anyway.

[rerpha]

https://github.com/ISISComputingGroup/EPICS/pull/417
ISISComputingGroup/EPICS-inst_servers#451

[rerpha]

no release notes needed as we were just testing this software anyway and no one should be depending on it.