QKeySequenceEdit: support '+' display for key combinations

As a user,

I would like to be able to configure QKeySequenceEdit to have a "+" indicator for key combination,

so that my shortcut editor will resemble similar applications.

At the moment, the key combination is short with the keys next to each other without a joining character, like "+" which is typically seen in some applications. One common example is VS Code.

I feel that it should be an opt-in property rather than opt-out as we probably ought to preserve the current default behaviour. I imagine that is what people typically use except some applications like Visual Studio Code.

Example video: https://code.visualstudio.com/docs/introvideos/customize

Update: although, they seem to have removed the plus in their recent version, so maybe the severity of this request is not so high.