Currently, the (X) close button is always shown and visible. In other words, it is not possible to configure the dialog component to NOT display this icon button. It is actually not just about the icon button, but also the ESC shortcut. It should not be possible to close the dialog when the input is set.

Feature request: Add an input `closable` for the Dialog Component ('kendo-dialog') to be able to turn off the closable behaviour. Example:

```html

  <kendo-dialog [closable]="false"></kendo-dialog>

```

The "closable" is `true` by default, ensuring that it is backwards compatible.

Use case: A certain dialog is presented to the user and user must NOT be able to close/ignore the dialog. The user is thus forced to resolve the instructions presented in the dialog and resolve it the intended way.