Add labels for benchmarks, fix #404

...ons/uc1-beam-flink/uc1-beam-flink-benchmark-operator.yaml

...ons/uc1-beam-samza/uc1-beam-samza-benchmark-operator.yaml

...s/definitions/uc1-flink/uc1-flink-benchmark-operator.yaml

...uc1-hazelcastjet/uc1-hazelcastjet-benchmark-operator.yaml

...nitions/uc1-kstreams/uc1-kstreams-benchmark-operator.yaml

...ons/uc2-beam-flink/uc2-beam-flink-benchmark-operator.yaml

...ons/uc2-beam-samza/uc2-beam-samza-benchmark-operator.yaml

...s/definitions/uc2-flink/uc2-flink-benchmark-operator.yaml

...uc2-hazelcastjet/uc2-hazelcastjet-benchmark-operator.yaml

...nitions/uc2-kstreams/uc2-kstreams-benchmark-operator.yaml

...ons/uc3-beam-flink/uc3-beam-flink-benchmark-operator.yaml

...ons/uc3-beam-samza/uc3-beam-samza-benchmark-operator.yaml

...s/definitions/uc3-flink/uc3-flink-benchmark-operator.yaml

...uc3-hazelcastjet/uc3-hazelcastjet-benchmark-operator.yaml

...nitions/uc3-kstreams/uc3-kstreams-benchmark-operator.yaml

...ons/uc4-beam-flink/uc4-beam-flink-benchmark-operator.yaml

...ons/uc4-beam-samza/uc4-beam-samza-benchmark-operator.yaml

...s/definitions/uc4-flink/uc4-flink-benchmark-operator.yaml

...uc4-hazelcastjet/uc4-hazelcastjet-benchmark-operator.yaml

...nitions/uc4-kstreams/uc4-kstreams-benchmark-operator.yaml