Fix metric naming and labling
Metric names and labels are confusing.
-
name
cannot be set on construction, which causes some problems with propegation of the name. If not set, it is auto-named, but seems not always useful. Have to also be careful that it is used in the serialization for AutoBenchmark. -
name
is used as the plot legend label, but breaks when math or other operations that derive a new Metric are applied -
label
,unit
: used as the y-axis label of the metric (should be "counts" by default), but can be changed for cases where the values are not counts, like "Effective area"