Every operation execution should lead to firing change event

[scofalik]

So, there was an idea that if the operation didn't do anything, it might not return any data and thus not cause model.Document to fire change event. For example, if RenameOperation renames from paragraph to paragraph, it didn't do anything in _execute, so why fire all the mechanisms (change dispatchers, conversion, etc.)

This is unfortunately a wrong concept. Even if it did resolved some problems, this is wrong. There might be a plugin that want to react to every applied operation and it might need to do something no matter whether the operation did change the model.

Skipping firing change event for some operations may lead to errors, for example if given plugin counts operations, want to retrieve something from history or bases on document version.