Transitioning to Binary Format in `fs-storage` Crate

We should consider migrating to a binary file format for the `fs-storage` crate. One potential crate is [bincode](https://crates.io/crates/bincode).
For context, I came across some benchmarks for Rust serialization frameworks, which could be valuable. You can find them [here](https://github.com/djkoloski/rust_serialization_benchmark?tab=readme-ov-file#raw-data).

Additionally, I just noted that the current output from `FileStorage` does not output a valid JSON file. The output is:
```
version 2
{"a":"1","b":"2","c":"3"}
```
It's also worth noting that the file doesn't have `.json` extension.