Id class for entity identification

[tshemsedinov]

Use common.Uint64 or common.BigInt64 to store Identifier. Note that we can't use Uint64 in globalstorage code and must use abstract Id of potentially infinite length. Id class should have two implementations for node 10 and above and for previous versions (using Uint64). Id instance is immutable, but we need to extract server suffix and object identifier inside server. Thus we need and operation to apply bitmask and shift operation.