common: Optimize the HDD mClock cost parameters.

common: Optimize the HDD mClock cost parameters.

With the earlier cost per io and cost per byte parameters, the
client ops performance was good but the recovery ops were taking
much longer to complete. The new cost parameters optimizes this
further so that the recovery ops progress faster while
maintaining similar client throughput.

This optimization is tested on both a small cluster and a larger
cluster in a scaled environment.

Fixes: https://tracker.ceph.com/issues/57529
Signed-off-by: Sridhar Seshasayee <sseshasa@redhat.com>