Use eth in queue

[Valdorff]

Design PR

• The idea is that we only put use 1 ETH for scrub check and the rest of the ETH can be used for assignments.
• This means all minipools need 31 ETH to get assigned. Here I only implement 16-ETH deposits.

Benefits:

• Single queue
  • 16, 8, 4, etc ETH deposits could sit in the same queue because, when in the queue, they all require 31 ETH.
  • I think adding another minipool type would only require editing RocketNodeDeposit.getDepositType to consider another deposit amount valid.
• ETH in queue is used productively - it increases rETH APR, similar to how ETH in the DP decreases rETH APR.

TODO

• Definitely missing the "efficient" queue
• Likely has errors from implementing; untested
• May have errors from rebasing onto v1.1, but I think I did ok?

[Valdorff]

Force push fixed an error in deposit. I had subtracted the 1 ETH used for prestake from the balance instead of the deposit. My b.