Make mechanisms module private

This patch makes the mechanisms module private.  The mechanism
implementation can still be accessed using the Mechanism enum.  This
leads to a clenaer public API and triggers a compiler warning if the
mapping between the Mechanism enum and the mechanism implementations is
wrong (as the implementation would then be unused).

Author: robin-nitrokey

CHANGELOG.md

@@ -65,6 +65,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Removed the `unsafe` keyword for the `Store` trait.
 - Removed the `unsafe` keyword for the `Platform` trait.
 - Replaced the mechanism RPC traits in `service` with a single `MechanismImpl` trait.
+- Made the `mechanisms` module private.  Mechanism implementation can still be accessed via the `Mechanism` enum.
 
 ### Fixed
 

src/lib.rs

@@ -32,7 +32,7 @@ pub mod error;
 pub mod interrupt;
 pub mod key;
 #[cfg(feature = "crypto-client")]
-pub mod mechanisms;
+mod mechanisms;
 pub mod pipe;
 pub mod platform;
 #[cfg(feature = "serde-extensions")]