Fix Delegator Migration Widget for Returning Delegators

[rickstaa]

The delegator migration widget is currently broken. This issue prevents delegators who wish to return after a migration from completing the process smoothly. We should investigate and resolve the problem so that returning delegators can successfully migrate and rejoin without errors or confusion.

[Jipperism]

Hi @rickstaa it would be useful to have a Definition of Done here. For reference, this is what the widget looks like now, for me locally.

The widget doesn't work, but I think it would be doable to get it functional again by wiring it up using the updated libraries from @ECWireless and possibly the arbitrum-sdk for estimating fees.

[rickstaa]

@Jipperism As we currently don’t have a testnet, verifying whether this issue is fully fixed is difficult. For now, success will be defined as follows:

• Fixed UI updates display correctly across devices.
• The updated logic does make sense based on the smart contract logic and tests pass.
  I’ve also reached out to users who still have unmigrated stakes on ETH and will update if I receive responses.