Perform upadateData through queue of replacements specified by
QBufferUpdate: start position (offset) and QByteArray (replacing data)
Add example based on custom-mesh-cpp to show how updating data works.
Task-number: QTBUG-50720
Change-Id: I2eceb514af21209deb278d73c94773e39f300fb3
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>