Add split coins into parts to qclient

[littleblackcloud]

Adds flags -p/--parts and -a/--part-amount, allowing you to split a coin into parts without needing to calculate and specifying the amounts.

Example - Split a coin into the specified amounts:

$ qclient token coins
1.000000000000 QUIL (Coin 0x1234)
$ qclient token split 0x1234 0.5 0.25 0.25
$ qclient token coins
0.250000000000 QUIL (Coin 0x1111)
0.250000000000 QUIL (Coin 0x2222)
0.500000000000 QUIL (Coin 0x3333)

Example - Split a coin into three parts:

$ qclient token coins
1.000000000000 QUIL (Coin 0x1234)
$ qclient token split 0x1234 --parts 3
$ qclient token coins
0.000000000250 QUIL (Coin 0x1111)
0.333333333250 QUIL (Coin 0x2222)
0.333333333250 QUIL (Coin 0x3333)
0.333333333250 QUIL (Coin 0x4444)

Note: Coin 0x1111 is the remainder.

Example - Split a coin into two parts using the specified amounts:

$ qclient token coins
1.000000000000 QUIL (Coin 0x1234)
$ qclient token split 0x1234 --parts 2 --part-amount 0.35
$ qclient token coins
0.300000000000 QUIL (Coin 0x1111)
0.350000000000 QUIL (Coin 0x2222)
0.350000000000 QUIL (Coin 0x3333)

Note: Coin 0x1111 is the remainder.

[littleblackcloud]

I couldn't find a more efficient way to query the amount of a specific coin address, so I adopted the approach from client/cmd/coins.go.

If there's a better way I'm happy to refactor :)

[tjsturos]

One suggestion: add a --amounts flag to create 3 equal tokens in that amount and the rest as a remainder.

E.g.

# Original token 0x0001 has amount 10.0000 QUIL
qclient token split 0x0001 --parts 3 --amounts 1

# coins after split using --amounts
qclient token coins
7.000000000000 QUIL (Coin 0x0002) # split automatic remainder
1.000000000000 QUIL (Coin 0x0003) # split part 1
1.000000000000 QUIL (Coin 0x0004) # split part 2
1.000000000000 QUIL (Coin 0x0005) # split part 3

[littleblackcloud]

Thanks for your suggestion @tjsturos! It's been implemented :)

[littleblackcloud]

Added tests for the split operations.

@CassOnMars let me know if you prefer a single commit per PR :)