EXOGTN-1815 Add supported-locale for I18NMessage.js and UIGadget.js

Fix description:
* I18NMessage.js generates the i18n labels for GateIn's Date Time Picker and Save, Cancel buttons when editing a gadget's setting
* UIGadget.js generates the i18n label for the confirmation when deleting a gadget.
PLF-6032: Add supported-locale of Romanian, Polish for I18NMessage.js and UIGadget.js