tests: Demarshalling of very long array/string lengths.

Attempting to demarshal message with array or string longer than its
body should return failure. Handling the length correctly is tricky when
it gets to near-UINT32_MAX values. Unexpected overflows can cause
crashes and other security issues.

These tests verify that demarshalling such message gives failure instead
of crash.

v2: Added consts, serialized opcode and size properly, updated style.
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Acked-by: Derek Foreman <derek.foreman.samsung@gmail.com>