Option to guard `hpa_min_purge_interval_ms` fix

Change in `hpa_min_purge_interval_ms` handling logic is not backward
compatible as it might increase memory usage. Now this logic guarded by
`hpa_strict_min_purge_interval` option.

When `hpa_strict_min_purge_interval` is true, we will purge no more than
`hpa_min_purge_interval_ms`. When `hpa_strict_min_purge_interval` is
false, old purging logic behaviour is preserved.

Long term strategy migrate all users of hpa to new logic and then delete
`hpa_strict_min_purge_interval` option.
6 files changed