Bool Button doesn't support runtime changes of the on_image or off_image

[kasemir]

See

https://epics.anl.gov/tech-talk/2022/msg00092.php

Can be reproduced by adding this script to the "Boolean Button_5" at the bottom of examples/controls_toggle_buttons.bob:

from org.csstudio.display.builder.runtime.script import PVUtil, ScriptUtil

# Configure script to use pvs[0] "sim://flipflop(2)"

if PVUtil.getDouble(pvs[0]) > 0:
    print("Original images")
    widget.setPropertyValue('off_image', 'pic/switch_off.gif')
    widget.setPropertyValue('on_image', 'pic/switch_on.gif')
else:
    print("Swapped images")
    widget.setPropertyValue('off_image', 'pic/switch_on.gif')
    widget.setPropertyValue('on_image', 'pic/switch_off.gif')