feat: implement comparison skeleton

This commit lays out the general idea of how the ComparisonData struct will work. It is expandable and I'm sure we will add more to it as time goes on.

src/lib.rs

@@ -2,6 +2,7 @@ pub mod app;
 mod common;
 mod components;
 mod pages;
+mod utils;
 
 #[cfg(feature = "hydrate")]
 #[wasm_bindgen::prelude::wasm_bindgen]