Refactor a bit

[msirringhaus]

Fixes #13 and splits a few big files into smaller chunks for easier handling.
No functional changes, only copy&paste.

Should also not be an API-change.

[Copilot]

Pull Request Overview

This PR refactors the WebAuthn implementation by extracting core logic into smaller modules without changing functionality or the public API.

• Moved PIN/UV authentication logic into pin_uv_auth_token.rs
• Introduced an error.rs to centralize error types for WebAuthn
• Updated imports across many files to reference the new modules and removed duplicated code from webauthn.rs

Reviewed Changes

Copilot reviewed 25 out of 25 changed files in this pull request and generated no comments.

File	Description
libwebauthn/src/webauthn/pin_uv_auth_token.rs	New module for PIN/UV auth token handling
libwebauthn/src/webauthn/error.rs	Centralized WebAuthn errors (Error, PlatformError)
libwebauthn/src/webauthn.rs	Removed duplicated implementations and added module imports
Multiple transport and management files	Updated imports to use the new error and PIN/UV modules

Comments suppressed due to low confidence (1)

libwebauthn/src/webauthn.rs:4

• The file uses Duration in several method signatures but no longer imports std::time::Duration. Please add use std::time::Duration; at the top to ensure the code compiles.

use async_trait::async_trait;

[AlfioEmanueleFresta]

Thank you so much for your work @msirringhaus!