Handy when one has the data buffer to be read in a QBAV.
This also fixes an issue and compiler warning about passing a
qsizetype data length value as an int, and makes it possible to pass
a qsizetype-size length without going through QByteArray.
Makes the QByteArray overload redundant.
Change-Id: Iba8825cf0fd8003fb2eac5b1d30a61ec91b85ceb
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>