Provide a 'title' property for the DialogAction objects in order to have the ability to configure a tooltip for the action buttons of the Dialog when DialogService is used.

Currently, there is no existing option for setting a title for the action buttons when they are passed as a collection of DialogAction objects to the actions property. A title can be set only when the action buttons are configured separately in a template:

• https://stackblitz.com/edit/angular-w685vt