Cleanup ArtificialNode__DO_NOT_USE

[potatowagon]

A followup task to #5857

During html pasting, ArtificialNode is a temp wrapper node to group nodes within block elements that should be separated by a linebreak (
). It is currently represented by a class extending ElementNode to be compatible with the typings in packages/lexical-html/src/index.ts.

A cleaner soln would be to not have ArtificialNode extend ElementNode so that it would not be confused as a LexicalNode. ArtificialNode is only used in the pasting logic and ideally should not need to be initialised in the Editor.

[jaapvanblaaderen]

Hi @potatowagon, when upgrading to Lexical to 0.15.0 I now get warnings in the console since ArtificialNode__DO_NOT_USE is not implementing methods required by ElementNode. I guess this is not be expected? Or am I maybe doing something wrong in the way I use Lexical?

ArtificialNode__DO_NOT_USE should implement "importJSON" method to ensure JSON and default HTML serialization works as expected
ArtificialNode__DO_NOT_USE should implement "exportJSON" method to ensure JSON and default HTML serialization works as expected
ArtificialNode__DO_NOT_USE must implement static "clone" method

[potatowagon]

@jaapvanblaaderen #6107 should fix the warnings

[potatowagon]

#6048 another fix

[MrPand-21]

I still get errors

ArtificialNode__DO_NOT_USE should implement "exportJSON" method to ensure JSON and default HTML serialization works as expected 
ArtificialNode__DO_NOT_USE should implement "importJSON" method to ensure JSON and default HTML serialization works as expected
ArtificialNode__DO_NOT_USE must implement static "clone" method

Is that because I use custom plugins?

[mudcube]

@MrPand-21 For npm version last build was 2-weeks ago, fix was posted 4-days ago.