Region should get enum

[guyluz11]

The region field is mandatory when login in to the account, I would prefer if there were a way to login to the account without inserting the region.
But if not let's change the region field to get an enum of all the supported countries, with that we can keep another factory method for inserting it by text.

Another thing about the region that it will solve is how I should use it.
In the official eWeLink app I am inserting region by selecting the country name plus 3 pre phone numbers.
So I am not sure in what way to insert the region, is it a full country name, 3 letters, 2 letters, pre-phone number numbers?.
Adding an enum will also solve this issue for future developers.

[guyluz11]

Found out in the docs that we can get the region for the user without specifying it manually

https://ewelink-api.vercel.app/docs/available-methods/getregion