fix(update): allow setting paths with dots under non-strict paths

[vkarpov15]

Fix #13434
Re: #10200

Summary

One of @AbdelrahmanHafez 's early issues #10200 pops up :) we shouldn't apply setDottedPaths() if schema is not strict and we don't have a schematype, because MongoDB supports storing paths with dots now.

Examples

[AbdelrahmanHafez]

LGTM, thanks!
One question though. How's this going to affect Mixed paths? Do we still split keys or this change would make it so that paths are now dot-separated?

[vkarpov15]

@AbdelrahmanHafez Schema({ info: Object }) is equivalent to Schema({ info: Mixed }), so the test case covers this. Mongoose would store { 'second.name': 'value' } rather than { second: { name: 'value' } }. However, this PR doesn't change that behavior, that's how Mongoose worked before this change.