thiserror, docs, remove general Failure case (#9741)

automerge

sdk/src/message.rs

@@ -184,6 +184,9 @@ impl Sanitize for Message {
                 }
             }
         }
+        self.account_keys.sanitize()?;
+        self.recent_blockhash.sanitize()?;
+        self.instructions.sanitize()?;
         Ok(())
     }
 }