V1 Improved `node deposit` and `node stake-rpl` flow

[thomaspanf]

Included in this PR:

• New suggested RPL stake options in stake-rpl, because changing node.per.minipool.stake.minimum to 0 broke the old selection

  Please choose an amount of RPL to stake:
  1: 5% of borrowed ETH (276.648996 RPL) for one minipool?
  2: 10% of borrowed ETH (553.297992 RPL) for one minipool?
  3: 15% of borrowed ETH (829.946988 RPL) for one minipool?

• Reintroduced the -y and -a flags to node deposit for users who automate minipool deposits (10/10 foresight)

• node deposit and create-vacant-minipool uses a y/n confirmation rather than prompting for a selection:

  
  // New
  NOTE: You are about to make an 8 ETH deposit.
  Would you like to continue? [y/n]
  y

// Old Please choose an amount of ETH to deposit: 1: 8 ETH 1

[thomaspanf]

Allow percents but make the user pass -a 5% instead of -a 5, otherwise it's a POLA violation when someone passes -a 5 and it stakes 5% instead of 5 RPL

TIL what a POLA violation is. Nice catch, thank you Patches!

[thomaspanf]

Thanks for tightening this up! Looks good now.

Always a pleasure, thanks for the review!