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

[jshufro]

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

[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!

[jshufro]

Can we drop the magic values and just use strings.EndsWith(c.String("amount"), "%") to determine if a percentage was passed? Then parse it and the actual amount.

[jshufro]

Just return the price and borrowed amount, and make the CLI calculate the percent of borrowed. This is an example of what I mean when I say the API over-fits the cli.