Provide low watermark for metastorage compaction

We should implement a process of increasing a low watermark for the metastorage compaction. I believe it should be a scheduled task in the top component (IgniteImpl) because it will needed information about open cursors and partitions.

MetaStorage compaction low watermark should be a subject to the following rules:
1. It cannot be higher than the Partition LWM.
2. It cannot be higher than any cursor's timestamp.
3. It cannot be higher than the timestamp of any schema version for which a tuple exists that is serialized using this schema.
4. It may be increased as soon as new LWM doesn't contradict all of the 3 points above.