Improved URL decoding to inline as needed and remove duplicate code

Author: dimitribouniol

Sources/WebPush/Helpers/DataProtocol+Base64URLCoding.swift

@@ -10,6 +10,7 @@ import Foundation
 
 extension DataProtocol {
     @_disfavoredOverload
+    @usableFromInline
     func base64URLEncodedString() -> String {
         Data(self)
             .base64EncodedString()
@@ -20,18 +21,16 @@ extension DataProtocol {
 }
 
 extension ContiguousBytes {
+    @usableFromInline
     func base64URLEncodedString() -> String {
         withUnsafeBytes { bytes in
-            Data(bytes)
-                .base64EncodedString()
-                .replacingOccurrences(of: "+", with: "-")
-                .replacingOccurrences(of: "/", with: "_")
-                .replacingOccurrences(of: "=", with: "")
+            (bytes as any DataProtocol).base64URLEncodedString()
         }
     }
 }
 
 extension DataProtocol where Self: RangeReplaceableCollection {
+    @usableFromInline
     init?(base64URLEncoded string: some StringProtocol) {
         var base64String = string.replacingOccurrences(of: "-", with: "+").replacingOccurrences(of: "_", with: "/")
         while base64String.count % 4 != 0 {