Handle precision and scale values for Decimal types

[ddimaria]

Currently, Decimal types are losing their decimal place. 321654.78 turns into 32165478 during the process (floats work as expected). I have a fork where I fixed this in case anyone is interested. My branch it a bit too far ahead to easily submit a PR on this repo, but I'd be happy to create one if the maintainer would merge it (not much activity since April).

Repo: https://github.com/quadratichq/snowflake-rs
PR to support Decimal types: quadratichq#3