Refactor RiskId #824
Description
- change type of RiskId to uint64
- check storage layout
- use ObjectCounter to generate ids https://github.com/etherisc/gif-next/blob/feature/chainid-type-refactoring/contracts/instance/base/ObjectCounter.sol#L9
- change
createRisk(https://github.com/etherisc/gif-next/blob/feature/chainid-type-refactoring/contracts/product/RiskService.sol#L42) to work the same way as request (https://github.com/etherisc/gif-next/blob/feature/chainid-type-refactoring/contracts/instance/InstanceStore.sol#L257)