rust/pv: Add-Secret: Add user-data types

Add four new user-data types an add-secret request could have:
Unsigned, Signed(EcSECP521R1, Rsa(2048, 3072))

As the user-data enum was not marked as non-exaustive this might be a
breaking change for users. (Not for any crate in this repo though).

The addition of such user-data is provided by following patches.

Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

rust/pv_core/src/error.rs

@@ -44,6 +44,9 @@ pub enum Error {
     #[error("Input does not contain an add-secret request")]
     NoAsrcb,
 
+    #[error("Input contains unsupported user-data type: {0:#06x}")]
+    UnsupportedUserData(u16),
+
     // errors from other crates
     #[error(transparent)]
     Io(#[from] std::io::Error),