Executes the action associated with this command.
Depending on the layout used for the current view, specific command containers will be available for commands added to this view. Depending on how you define command mapping, the command will be displayed by a specific item of the widget that serves as a command container. When clicking the widget item, the execute() method will be be called for the associated command. This method performs the function assigned to the onExecute command option or calls the navigate() function to navigate to the URL specified for the onExecute command option.