Switch from using template.json to using DataModels

[xdy]

See https://foundryvtt.com/article/v10-data-model/ and https://foundryvtt.com/article/system-data-models/

It seems to pass the 'Works On My Machine(tm)' test. :)

Possible next steps, in no particular order:

• Move migrations to datamodel.
• Use polymorphism to split actor and item into one object per type with a common ancestor.
• Move appropriate logic to the datamodel.

[pafvel]

I haven't really looked into datamodels yet, so this will have to wait a little. At least until after the v12 upgrade. Is there anything in particular that you want to do that requires the system to use datamodels instead of template.json?

[xdy]

Yeah, no worries. Shouldn't really conflict with anything that for that I'd think.

As for why I did it, well, I don't really have a goal yet, mostly exploring the codebase, wanted to do something potentially useful and the remaining issues didn't seem that interesting to me, so, I went back to my usual work mode of taking something that's deprecated/near eol and replacing it with something that's not. :) (Also, tbh, as a way to procrastinate on upgrading my pf2e qol/automation module to support v12, some of the changes felt too annoying to dig into right now.)

Haven't even gotten to actually play DoD yet, so I barely know what painpoints exist when using the system, but I'm getting a bit tired of pf2e so will try to lobby for DoD again. Or just force my players to play it. One of those... (We're all Swedes, but got into english language rpgs back in the 80s, and mostly kept playing in english, coc/rq/traveller/gurps/hero/d&d, etc, so I'm kind of looking forward to not having to awkwardly translate things on the fly all the time.)

/Jonas