Add textNode.isEmpty member

[jacekbogdanski]

Type of report

Feature request

Provide description of the new feature

The function should check whether the text node is empty or its value is set to CKEDITOR.dom.selection.FOLLOWING_CHAR_SEQUENCE which should be treated as an internal string, not real text node value.

[Comandeer]

I propose adding optional parameter ignoreWhiteSpace to cover one more use-case: https://github.com/ckeditor/ckeditor-dev/blob/64749bb245d1e91f6a4ac4e97c9648ec47acda91/core/dom/element.js#L1021

[jacekbogdanski]

I would avoid passing flag boolean parameters to methods which makes them less obvious to work with. Maybe let's go with additional member isBlank? Seems like a super simple method but much more verbose.

[Comandeer]

IMO isEmpty and isBlank sounds too similar and I can imagine having trouble with differencing between these two, always checking docs to choose the right one.