Optimize metrics of minute dimensionality persistence, don't save metric of being default value. (#8066)

Optimize metrics of minute dimensionality persistence.
- The value of metrics, which has declaration of the default value and current value equals the default value logically, the whole row wouldn't be pushed into database.
- Add self-observability `metrics_persistence_skipped` metric to measure the number of skipped metrics.
- SLA(percent function), Apdex, AvgLong(MAL mostly) metrics are mostly optimized because of this. Such as a full-failing error(0% successful rate) and unhealthy(apdex=0) are not costing the storage.
- Hour/Day dimensionalities metrics are not changed, as they cover long duration.
- Fix `max` function in OAL doesn't support negative long.