use `f64` (double) over `f32` precision in the Parser

## Research whether:
- We need `f64` accuracy for any of the fields? - Yes, complexity will be lower by just using double precision.
- If it's really needed, then how we can allow both `f32` and `f64` in the parser (a choice that will be given to the user of the crate)? - No, it is not needed

# TODOs:

Replace all places to use `f64` (double) precision rather than complicating the source code.