Use incremental backup/restore for snapshots

[abramsymons]

The most time-consuming part of the scorer service is currently restoring the snapshots.
Incremental backup/restoring method can be used to improve the scorer's performance.
The most important collections in the snapshots are connections, connectionsHistory which new records are added to very slowly so the incremental method works great for them. Another collection is verifications which seems has huge changes in every period but it seems that it can be removed from the snapshots without making any problem.