Preview addon should use editor's "title" property for the title of the new window

[spacevoyager78]

Type of report

Feature request

Provide description of the new feature

Currently, Preview addon uses its name for the title of the new windows that is create, as you can see in its source code: https://github.com/ckeditor/ckeditor4/blob/major/plugins/preview/plugin.js#L100
title = editor.lang.preview.preview,
However, since you can use print function to create pdf files via pdf printers or internal pdf function of chromium-based browsers, I think it should use title property of editor instance, so as to have a default pdf filename that resembles the editor title.
So, I propose that the above line in code should be changed from
title = editor.lang.preview.preview,
to
title = editor.title,

[jacekbogdanski]

Indeed that makes sense, thanks @WiZaRD13 👍 As you already did some research on this topic, maybe you would like to propose PR for this improvement?

Also, note that print plugin also uses preview under the hood, so it probably would also profit from this improvement.

[spacevoyager78]

I'm sorry, I'm really ignorant about PR and the whole procedure, plus I don't have much time right now...

[CKEditorBot]

Closed in #4915