chore: Replace uses of model skill with MM's Model property

[0ffz]

The model skill should only be used inside other skills, where it's impossible to assign it directly in the config (ex. if multiple mobs need to be configured via a spawn skill).

In any other case, the Model tag on the actual MM entity should be used. It's also worth nothing that some mobs do assign their model through a separate spawn skill, but I believe it's better to just use Model in these cases as well.