Add qTrId() alias for qtTrId()

For id-based translations in C++ code we have the function qtTrId. It was introduced with the following comment:

// Defined in qcoreapplication.cpp
// The better name qTrId() is reserved for an upcoming function which would
// return a much more powerful QStringFormatter instead of a QString.
Q_CORE_EXPORT QString qtTrId(const char *id, int n = -1);

QStringFormatter never materialized, though. See https://lists.qt-project.org/pipermail/development/2017-August/030677.html

Standard C++ has std::format now, but it's questionable whether qTrId should wrap it or aid format strings in another way.

Consider adding qTrId as alias for qtTrId.
Or at least remove the comment.