[Feature Request] Add updateOrCreate/firstOrCreate

[vesper8]

Describe the feature

These are some of the most-used eloquent helpers in Laravel, I personally use updateOrCreate a lot and it would be nice to have it in pinia-orm so I don't have to do things like this:

        if (useRepo(Requirement).find(id)) {
          await useRepo(Requirement)
            .whereId(id) //
            .update(this.form);
        } else {
          await useRepo(Requirement).save({
            id: useRepo(Requirement).all().length + 1, //
            ...this.form,
          });
        }

Additional information

• Would you be willing to help implement this feature?

Final checks

• Check existing discussions and issues.