Qt 6: Mnemonics "leak" in editor's dock titles

[lah7]

With the port to PyQt6 (#508), there seems to be a Qt 6 bug where the & character appears in the text in these QDockWidget titles.

Technically known as mnemonics, they allow users to activate/focus by using the keyboard's ALT key. Since the default Polychromatic uses the default "Fusion" style underneath, they're always visible (with no way to disable this, unfortunately).

Example 1	Example 2
image

It seems that Qt 6 may be automatically creating these mnemonics when not defined, but it looks like a rendering bug out of our control. Trying to remove & from the string doesn't work.

Workaround is to use the system theme. For example, with KDE, the "Breeze" style does not show them unless ALT is pressed.