[Types] Re-add the possibility to pass undefined for projection in Model.find

[ghost91-]

Summary

This re-adds the possibility to pass undefined as projection to the find method of models.

Examples

  Project.find({}, undefined, { limit: 5 });

(see the added tests for more details)

[AbdelrahmanHafez]

LGTM, thanks! 👍

[AbdelrahmanHafez]

@ghost91-
Should we also do the same for .findOne/findOneAndUpdate/findById?

[ghost91-]

For those, it's already done, if I am not mistaken. undefined is not listed explicitly, but the parameters marked optional. Unless you are using the exactOptionalPropertyTypes option, it results in the same thing. I just tend to specify undefined explicitly because I sometimes use that option.

Granted, there also are no tests for the other methods, so it may be worth adding some.

[vkarpov15]

Thanks 👍