[all_sites] Fix bmc_node_power_watt_total unit (watthour)

data/grid5000/sites/nancy/clusters/grue/grue.json

data/grid5000/sites/nancy/clusters/grvingt/grvingt.json

data/grid5000/sites/nantes/clusters/ecotype/ecotype.json

data/grid5000/sites/rennes/clusters/parasilo/parasilo.json

data/grid5000/sites/rennes/clusters/paravance/paravance.json

...t/grid5000/sites/grenoble/clusters/dahu/dahu_metrics.yaml

...grid5000/sites/grenoble/clusters/troll/troll_metrics.yaml

...t/grid5000/sites/grenoble/clusters/yeti/yeti_metrics.yaml

...rid5000/sites/lille/clusters/chetemi/chetemi_metrics.yaml

...rid5000/sites/lille/clusters/chiclet/chiclet_metrics.yaml

...d5000/sites/lille/clusters/chifflet/chifflet_metrics.yaml

...d5000/sites/lille/clusters/chifflot/chifflot_metrics.yaml

.../luxembourg/clusters/petitprince/petitprince_metrics.yaml

input/grid5000/sites/lyon/clusters/nova/nova_metrics.yaml

input/grid5000/sites/lyon/clusters/orion/orion_metrics.yaml

...t/grid5000/sites/lyon/clusters/taurus/taurus_metrics.yaml

...d5000/sites/nancy/clusters/graffiti/graffiti_metrics.yaml

...d5000/sites/nancy/clusters/graoully/graoully_metrics.yaml

...000/sites/nancy/clusters/graphique/graphique_metrics.yaml

...d5000/sites/nancy/clusters/graphite/graphite_metrics.yaml