Add support for MAX_EB deposit sizes

[CarlBeek]

EIP-7251 also known as MAX_EB is a part of the Pectra hardfork. It allows validator balances to grow up to 2048 ETH.

The goal of this is to have fewer validators on the network and so on the launchpad, we should encourage and support larger deposits (ideally up to 2048 ETH before creating a second validator).

This means we need to change the logic around how we handle deposits from being determined by the number of validators a user would like to create to basing this off of the size of deposit they would like to make.

I have written an example python script to evenly split a deposit among as few validators as necessary:

https://gist.github.com/CarlBeek/3e51f25980dfb367d80d6788f9e05ee5