Use cfg aliases throught the code base

Co-authored-by: Mads Marquart <mads@marquart.dk>

examples/web_aspect_ratio.rs

@@ -2,7 +2,7 @@ pub fn main() {
     println!("This example must be run with cargo run-wasm --example web_aspect_ratio")
 }
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(wasm_platform)]
 mod wasm {
     use wasm_bindgen::prelude::*;
     use wasm_bindgen::JsCast;