Eliminate redundant local region RegionSpecificSeqId, which can be compensated by local component id as upper bound.

The original usage of local region RegionSpecificSeqId was for Graph service, which is no longer pursued.

RB_ID=128053
Adjust default configurations, remove unused configurations, and cancel speculative read once future instance will not happen (heardFromHosts is never reset, so future call of maybeSendSpeculativeRead will not return non-null once it returns null).

RB_ID=128201
Update default configuration options
- Maxwait = 200ms
- FlushWhenQueueEmpty = false

Create a common config for tests so that we can override the defaults

RB_ID=128116
Make checkpoint policy strict w.r.t. marker comparison, to minimize redundant ledger entries replayed. This also helps smooth mem-table flush cycles.

RB_ID=128306
improve close logic

- when someone already closed the ledger handle, we don't need to close it again. otherwise, it might cause lots of metadata update failure due to bad version in zookeeper. it would happen when encountering unrecoverable exception, e.g BkNotEnoughBookieException
- remove unneccessary log statement in bookkeeper persistence manager, since it might be called several time when failing several add entries operations due to BkNotEnoughBookiesException

RB_ID=127579
 Add ramp up time to rate limiter
 - Add ramp up time to rate limiter
 - Add first publish success message

RB_ID=128413