v1.18.1

Staking Security Improvement and Bug Fix

Main Changes

• add pausing & freezing of staking
• fix bug - prevent arbitrary increase of delegated VP
• fix ExtendedStakingTest - staking duration change test
• add new StakingLogic6 to mainnet_contracts.json

Full Changelog: https://github.com/DistributedCollective/Sovryn-smart-contracts/commits/v1.18.1