The Merge: Support fee recipient for validator accounts

[daGscheid]

As soon as the merge hits, validators will be able to specify a fee recipient in their consensus client.
This is possible for either the whole node or specific keys.

To support this fee recipient function we need:

• [x] #505
• [x] #506
• [ ] #508

[daGscheid]

#571 Beacon Chain API Call for "Block Fee Recipient"

[daGscheid]

With #1264 @NeoPlays added the necessary backend for this. I would propose the following button - taking the middle spot for button on the key

For the input we reuse what @MaxTheGeeek made for "Validator Naming", changing the input to only take Ethereum Addresses

Slightly changing the color: HEX COLOR #4D56CB & using this icon to represent it:

Bc Max is kind of overloaded I would propose @mabasian to do this, but please ask him about the Validator Naming component and just reuse most of it 👍