TextFloat does not work under Wayland

### System Information

Arch Linux with Wayland

### LMMS Version(s)

master

### Bug Summary

Positioning the text float window does not work under Wayland. All text floats are shown at position (0, 0) instead of at the lower left corner of the main window like under X11.

The reason is that `TextFloat::moveGlobal` uses [QWidget::move](https://doc.qt.io/qt-6/qwidget.html#pos-prop) which is not supported under Wayland.

### Expected Behaviour

The text float should not show at (0, 0).

Proposal: Implement a dedicated area where messages are shown and collected instead of using an ephemeral text float which users might miss to notice anyway.

### Steps To Reproduce

Open a project that has been created with an older version of LMMS so that the text float which shows that information is displayed.

### Please search the issue tracker for existing bug reports before submitting your own.

- [X] I have searched all existing issues and confirmed that this is not a duplicate.

Start at TextFloat::moveGlobal and inspect its use of QWidget::move, then reproduce the older-project migration message on Arch Linux with Wayland. Done means the text float or replacement message presentation is no longer rendered at (0, 0) and appears in an accessible location consistent with the expected lower-left placement.

Written by the indexing model from the issue text.