ezidam + jwt: get key, import private key, create jwt claims and sign them

crates/jwt/src/database.rs

@@ -44,6 +44,10 @@ impl Key {
     pub fn public_der(&self) -> &[u8] {
         &self.public_der
     }
+
+    pub fn is_revoked(&self) -> bool {
+        self.revoked_at.is_some()
+    }
 }
 
 impl From<DatabaseKeys> for Key {