Correct consolidation amount display

When presenting the information for a consolidation from one validator to another, we show all the balance going from the source to the target on the confirmation pop-up but that is wrong.

The protocol is defined here: https://github.com/ethereum/consensus-specs/blob/dev/specs%2Felectra%2Fbeacon-chain.md#new-process_pending_consolidations. It will move the minimum amount from the source validator between the effective balance and the actual balance. Your effective balance can be higher or lower than your actual balance depending on the current hysteresis zones (see ). In the case where your effective balance is higher than your actual balance, your full actual balance will be moved to your target validator. In the most likely case where your effective balance is lower than your actual balance, only the effective amount will be moved to the the target validator and the remaining will be withdrawn to your original withdrawal address.

We should improve the way we display this information so that users are aware of where their money is going.