Implement updateStrategyMaxDebtPerHarvest

[MickdeGraaf]

User Story

• As an <audience/user>: PieVault admin
• I want to <action/task>: be able to change the max amount that can be harvested from a strategy
• so that <outcome/goal/benefit>: Can limit how much is harvested

Type

• Enhancement
• Maintenance
• Refactor

Description

Needed to reach Yearn strategy compatibility

Definition of Done

• Implemented updateStrategyMaxDebtPerHarvest
• Unit test updateStrategyMaxDebtPerHarvest

Part of #30
Partly implemted in yearn-strategy-support