Enable Unicode support in QRegularExpression where needed
This fixes a QRegularExpression porting bug: QRegExp is always Unicode-aware whereas with QRegularExpression Unicode support can be optionally enabled by setting the UseUnicodePropertiesOption flag.
KMimeTypeChooser: because it's a sort proxy model, and it should handle user input, I am guessing on localised systems it could be useful to have QRegularExpression with Unicode support
KCharSelect: well, this is "Unicode" all over the place