Avoid using InfoMetricFamily when possible #87
Description
I think it's not a good practice to just dump content using InfoMetricFamily and then need to have to query using labels.
E.g:
canonical/hardware-observer-operator#354 shows that the ssacli_controller is giving false alerts.
It's cleaner in my opinion if we return 1 for OK 0 for DOWN and -1 for unknown or others.
This can simplify expressions, so instead of using something like:
ssacli_controller_info{status!~"^(OK|NOT CONFIGURED)$"} we could just use ssacli_controller_info == 0
Moreover, I think it's easier to identify if ssacli changed the output if we observe that all metrics are returning -1 instead of checking the status. Always returning 1 with InfoMetricFamily is way less expressive