Refact(client): New core client implementation #65

src/aura_engine/base/exceptions.py

src/aura_engine/client/connector.py

src/aura_engine/client/playerclient.py

src/aura_engine/core/client.py

src/aura_engine/engine.py

src/aura_engine/mixer.py

src/aura_engine/plugins/mailer.py

src/aura_engine/plugins/monitor.py

src/aura_engine/scheduling/scheduler.py