controlId - id of the brixxbox control as a string
visible - (optional, default = true) bool value if the control should be visible or not
subControl (optional) Some controls have sub Controls, that can be set visible or hidden. Important: setVisibility for subcontrols cannot be used in onAppStart, because some controls are not fully created at that time, use onAppInitialized instead. Here is a list of possible subControls:
grids - The grid toolbar has to be active to see buttons at all!
buttons - shows or hides the buttons of a grid
buttonNew - shows or hides the new buttons of a grid
buttonDelete - shows or hides the delete buttons of a grid
buttonCopy - shows or hides the copy buttons of a grid