Unlike simplified(), it just moves the end-points, without needing to
modify contents, so it makes sense (as for QStringView and
QLatin1String) to provide it. Moved QByteArray's trimmed() tests to
tst_QByteArrayApiSymmetry so that QBAV can now share them.
[ChangeLog][QtCore][QByteArrayView] Added trimmed().
Change-Id: Ifd7a752adb5f3d3e2ad0aa8220efa7e7d2d39baa
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>