PR description:
> PR14383 moved the debug window's menu position, to make it conditional on wallet mode. The rationale given was to match the behaviour of the 'Help' menu.
>
> PR14573 replaced the 'Help' menu's conditional debug window with an unconditional list of items in the new 'Window' menu.
>
> This PR reverts the no-longer-applicable part of #14383, putting the debug window back on the tray menu unconditionally, and in the position it previously had.
This is a backport of Core PR15023
Depends in D8146