QA-T849

Custom Widget can be added to app and interacted with in the following ways:

• The read/write props of the widget can be set to two datasources: variable and table record 
• Readonly props of the widget can be set to several datasources: variable, app info, table record, static value, table aggregation
• Events of the custom widget can be configured in the app editor
• Data sources propagate accurate data in through the custom widget and configured events fire correctly and completely