Closing dialogs via standart eventing system instead of using postal events

[oleh-maikovych]

Description

Previously dialog closing logic on save or cancel actions were implemented via postal events. But such approach proved to be cumbersome when it comes to managing centreUuid of action and entity master. But master action that triggeres postal close event is a descendant of dialog, therefore in that case standard eventing system can be used to trigger dialog close event. This approach eliminates the need to manage centreUuid for dialog closing purpose.

Expected outcome

More managable dialog closing logic.