feat: implement nested routes for loaner form

We're using this as our testing ground before attempting to refactor all other pages as well.

.cargo/config.toml

@@ -6,3 +6,6 @@ rustflags = [
 
 [target.wasm32-unknown-unknown]
 rustflags = ["--cfg=web_sys_unstable_apis"]
+
+[target.'cfg(target_os = "windows")']
+rustflags = ["--cfg=web_sys_unstable_apis"]