CBOR wrappers: proper error message order (#7572)

Author: maxtropets

src/crypto/cbor.h

@@ -88,7 +88,7 @@ namespace ccf::cbor
     {
       if (!msg.empty())
       {
-        throw CBORDecodeError(fmt::format("{}: {}", err.what(), msg));
+        throw CBORDecodeError(fmt::format("{}: {}", msg, err.what()));
       }
       throw err;
     }

src/crypto/test/cbor.cpp

@@ -1454,7 +1454,7 @@ TEST_CASE("CBOR: throw with context")
 
   const std::string context = "Custom enough context";
   const std::string err = "Not a string value";
-  const std::string expected_err = err + ": " + context;
+  const std::string expected_err = context + ": " + err;
   REQUIRE_THROWS_WITH_AS(
     rethrow_with_msg([&]() { std::ignore = v->as_string(); }, context),
     expected_err.c_str(),