feat: impl lossy_from(f64)

[OliverNChalk]

Example for how to extract the mantissa & exponent:

fn raw_mantissa_and_exponent<T: PrimitiveFloat>(x: T) -> (u64, u64) {
    let bits = x.to_bits();
    let mantissa = bits.mod_power_of_2(T::MANTISSA_WIDTH);
    let exponent: u64 = (bits >> T::MANTISSA_WIDTH).exact_into();
    let exponent = exponent.mod_power_of_2(T::EXPONENT_WIDTH);
    (mantissa, exponent)
}

[OliverNChalk]

Actually, need to re-think if this is useful or if we should just provide a decimal! macro