Function updatePrecisionToDisplay

Update the amount to display precision equivalent to ~0.01 of the native price or use most significant decimal if the updated precision amounts to zero

A simplification of how this is done:

1. Floor nativePrice into an integer. Take the number of significant digits of the result as x. (significant digits include 0s, and 0 has 1 significant digit)
2. Round amount to x + 2 decimal places, rounding down, taking the result as r.
3. If r is not 0 return amount rounded to x + 2 decimal places, rounding up if roundUp is true and rounding down otherwise
4. If r is 0, instead return amount truncated (not rounded) to 1 significant digit

Example

updatePrecisionToDisplay(0.000357, 0.1) // '0.0003'
updatePrecisionToDisplay(0.000357, 10) // '0.0003'
updatePrecisionToDisplay(0.000357, 100) // '0.00035'
updatePrecisionToDisplay(0.000357, 1000) // '0.000357'

updatePrecisionToDisplay(0.000357, 100, true) // '0.00036'