Use new persistent store library (and delete old)

src/ctap/status_code.rs

@@ -81,5 +81,17 @@ pub enum Ctap2StatusCode {
     /// This type of error is unexpected and the current state is undefined.
     CTAP2_ERR_VENDOR_INTERNAL_ERROR = 0xF2,
 
+    /// The persistent storage invariant is broken.
+    ///
+    /// There can be multiple reasons:
+    /// - The persistent storage has not been erased before its first usage.
+    /// - The persistent storage has been tempered by a third party.
+    /// - The flash is malfunctioning (including the Tock driver).
+    ///
+    /// In the first 2 cases the persistent storage should be completely erased. If the error
+    /// reproduces, it may indicate a software bug or a hardware deficiency. In both cases, the
+    /// error should be reported.
+    CTAP2_ERR_VENDOR_INVALID_PERSISTENT_STORAGE = 0xF3,
+
     CTAP2_ERR_VENDOR_LAST = 0xFF,
 }