As part of T384725: [Epic] WE4.2.18 UserInfoCard experiment for assisting patrollers and moderators, the feature would like to store additional data in the UserImpact module for later use in the card. To minimize disruption to the module, we should:

• Add a new property, userInfo to the UserImpact class (as well as any necessary utilities)
  • This property is an unstructured JSON blob
• Add a hook where necessary to allow extensions to declare data to write to UserImpact and that data should be written to the userInfo property
  • This should cover the maintenance script, on-demand calcs, etc

Acceptance Criteria

• As above
• T386435: UserInfoCard: Create service to return user info card data for an account should be able to see this property