fix: return rate in/out as number (#3798)

The return type for `rateIn`/`rateOut` should be a number and not an integer.

go-IPFS returns a `float64` which isn't representable in js, but we are not interested in that level of accuracy for this value so just return it as a regular `number` which can be a `float`.

Fixes #3782

BREAKING CHANGE: rateIn/rateOut are returned as numbers

src/stats/bw.js

@@ -21,8 +21,8 @@ module.exports = configure(api => {
       transform: (stats) => ({
         totalIn: BigInt(stats.TotalIn),
         totalOut: BigInt(stats.TotalOut),
-        rateIn: BigInt(stats.RateIn),
-        rateOut: BigInt(stats.RateOut)
+        rateIn: parseFloat(stats.RateIn),
+        rateOut: parseFloat(stats.RateOut)
       })
     })