feat: Validate country input during student registration

[Waleed-Mujahid]

Description

While using the CSV enroll option in LMS instructor tab if an instructor use full country name instead ISO country code a general DataError is raised which can be confusing for instructors.

Roadmap

openedx/platform-roadmap#487

Before

After

Testing instructions

1. Set ALLOW_AUTOMATED_SIGNUPS as True in site configurations
2. Open a course on LMS as instructor
3. Click on Instructor tab
4. Click on membership
5. Upload a csv with fields in correct order
6. For country give value in Non-ISO code format
7. A verbose error will be returned instead of a general DataError

[Waleed-Mujahid]

@mphilbrick211 Hey can you look into this PR and the linked issue

[mphilbrick211]

Hi @Waleed-Mujahid! Is this currently for a product proposal that's in progress? It might be that the Product team has not had a chance to review yet.

[Waleed-Mujahid]

@mphilbrick211 hey the product review is complete. Can you ask someone to review this?

[ayub02]

I agree with this change. Also commented with my approval on related issue: openedx/platform-roadmap#487

[ChrisChV]

We're not eliminating spaces in the country; something like " US" is failing.

Suggested change

	if not Country(country).name:
	if not Country(country.strip()).name:

[ChrisChV]

Before these changes, for an existing user (only for enrollment), the country column wasn't used. But now it's checked, and this can generate errors. Can you only perform this check for new users? This would make it backward compatible.

[ChrisChV]

Before the changes, users could be created with an empty country code; now, the new checks generate an error.

[ChrisChV]

Hi @Waleed-Mujahid, nice work! I've left some comments. Thanks!