fee rate is whole HNS

https://hsd-dev.org/api-docs/?shell--cli#send-a-transaction

```
the rate for transaction fees. Denominated in subunits per kb
```

I don't think this is right. Internally in hsd, `rate` is treated as an int, a number of dollarydoos. But actually what you enter into `hsw-cli` is a float, that gets multiplied `*10e6`:

https://github.com/handshake-org/hs-client/blob/533b1403f381c086fc364545d88410fc38e8c0f4/bin/hsw-cli#L375

```
rate: this.config.ufixed('rate', EXP),
```