Part of speech not available in snapshots

[myieye]

Describe the bug

The following code means that the part of speech is shown as "none" in snapshots:

languageforge-lexbox/backend/FwLite/LcmCrdt/Changes/SetPartOfSpeechChange.cs

Lines 26 to 28 in 5190ba2

	entity.PartOfSpeechId = partOfSpeech.Id;
	//don't set the part of speech, it may trigger an insert of that part of speech
	//I wasn't able to figure out how to write a test to cover this sadly, I only saw it live.

Semantic domains, in contrast, are shown in snapshots.
The difference is that semantic-domains are stored as json directly on senses, while a part of speech is referenced.
That decision doesn't feel deliberate to me.

Expected behavior
It's confusing that project activity and history don't properly reflect part of speech changes.
I think it should.

First we'd need a test, which according to the comment, is maybe non-trivial, though I'm hopeful.

Also, we could solve this by loading the part of speech before displaying a snapshot, but I think it would be handy if we could put (more) things on snapshots instead of having to load it.