Short-circuit DynamicTraceEventParser::GetPayloadValueAt for arrays of bytes
Short-circuit DynamicTraceEventParser::GetPayloadValueAt for arrays of bytes

For reasons I'm not going to get into, we are using the DynamicTraceEventParser class to retrieve a payload value of a byte array. Its very inefficient; there is already a TODO in the codebase to handle arrays of blittable types more efficiently. I did some brief testing where I emited a single event, captured and opened up that file using the DynamicTraceEventParser, cloned the event, then read a single 2000 byte payload value 10000 times from that clone. Using perfview against this simple harness show as 5x reduction in CPU.

My change looks a little hackish, but seems safe enough until that existing TODO is properly addressed. Existing tests pass.

vancem/perfview,vancem/perfview,vancem/perfview,vancem/perfview,vancem/perfview