Rust for unpacking and formatting rain stack items

[hardyjosh]

@thedavidmeister has implemented a new math and number library for rainlang

This means that stack values aren't integers anymore, but are actually packed floats

We need complementary rust code that will help us unpack and format stack values for use in the charts and debug table in the app

https://github.com/rainlanguage/rain.math.float/blob/34801621f7a0e3c6151d693eadb1677c7b8b8995/src/lib/LibDecimalFloat.sol#L268

[thedavidmeister]

@hardyjosh is this still the plan? or have we moved to having rust simply hand off to an evm for float math?