Bonus rewarder

[ChiTimesChi]

Description

Adds BonusRewarder, a MinChefV2 extension enabling double rewards for any of the pools present in MiniChefV2.

Every pool in MiniChef can be assigned allocation points for the bonus rewards. In order to opt in for the bonus rewards, user will have to interact with MiniChefV2 after the bonus rewarder was added.

Checklist

• New Contracts have been tested
• Lint has been run
• I have checked my code and corrected any misspellings

[ChiTimesChi]

Things left to do:

• Make bonus rewards last for a certain amount of time
• Add tests for bonus rewards targeting more than one pool

[ChiTimesChi]

Main difference between BonusRewarder and MiniChef is that the bonus rewards are paid on every interaction. If contract doesn't have enough tokens to pay, the unpaid rewards are recorded, and paid out on the next user interaction (provided the contract was refilled).

New things:

• Ability to set a deadline for the bonus rewards (for all pools at once)
• Ability to claim bonus rewards once BonusRewarder is removed from MiniChef
• Fixed bug: user who left the pool, but has unpaid rewards, should be able to harvest these rewards without having to deposit again