I cannot remember any addon doing this and it would also be very complicated to add this to all controls.
Often controls are "anchored" to others or get influenced by others (scenes/fragments).
There are ways to bring a control to the most top but it could be changed on next movement or menu close again by the standard game code (vanilla code).
You can try this in your chat editbox with the mouse cursor above a control:
Code:
/script moc():SetDrawTier(DT_HIGH)
moc() will get the control below the mouse cursor.
If you get any error message moc() is not working or no control was found or it does not provide the SetDrawTier function.
If things get f***d up just do a /reloadui in chat to restore the old values.
This is the same script as above only with some security checks to prevent lua error messages or bringing the complete GuiRoot to the front:
Code:
/script local m=moc() if m and m ~= GuiRoot and m.SetDrawTier then m:SetDrawTier(DT_HIGH) end
Instead of DT_HIGH you can also use these:
DT_MEDIUM (standard value for controls)
DT_LOW