Symbian: There should be an input method hint to switch to "text case" (auto uppercase), aka Qt::ImhPreferAutoUppercase

There should be a QWidget::inputMethodHint to indicate that autouppercase mode is preferred. Auto uppercase mode is the "Abc" mode on Symbian phones, as opposed to "ABC" or "abc".

The reason is that currently, you can enable autouppercase by simply leaving out both uppercase and lowercase flags and Qt will then make the mode available among the input modes. However it is not possible to switch to it, if the mode is already another case. Therefore it should be possible to set it as the preferred mode.