Fix update only stream name also set default to timezone and country code

[Tooseriuz]

✅ DoD

• Resolves Update site name from Arbimon make timezone to default UTC #584
• API docs updated na
• Release notes updated na
• Deployment notes updated na
• Unit or integration tests added na
• DB migrations tested na

(use na when API docs (Release notes, etc) do not need to be updated)

📝 Summary

• Fix converter cannot take null value in request query and body
  • Before, if we send null value, the converter will take it out which I think it is not user's intention. If we add null to request body, it means we want to set it as null.
• With above converter not taking null. it causes us
  • assume we have stream with latitude = 10, longitude = 100. and we update it with latitude = null. in the current API it will not update to null and also cause timezone and country code to be default

[veckatimest]

```
if (this.required && this.src[this.property] == null) {
  this.throwError('the parameter is required but was not provided')
}
```

we should probablyu also throw error if required and this.src[this.property] === undefined

[veckatimest]

if ([null, undefined].includes(this.src[this.property]) {
   throw...
}

[veckatimest]

or even just undefined

[Tooseriuz]

== null is already included null and undefined @veckatimest

[veckatimest]

Oh, I see. I just feel like we should avoid '==' at all costs (but it's up to you).

[veckatimest]

at this point we already know that latitude and longitude are not undefined, right?

[Tooseriuz]

yes you're right