Use explicit imports in unified.rs tests

Switch the module tests within unified.rs to use explicit use statements
instead of glob imports (*). This improves code clarity by clearly indicating
which items are being brought into scope.

Author: chuksys

src/payment/unified.rs

@@ -390,8 +390,7 @@ mod tests {
 
 	use bitcoin::{address::NetworkUnchecked, Address, Network};
 
-	use super::*;
-	use crate::payment::unified::Extras;
+	use super::{Amount, Bolt11Invoice, Extras, Offer};
 
 	#[test]
 	fn parse_uri() {