[Backport to release/10.3] Retrieving two-letter country code from the three-letter code with league/iso3166 + additional fixes

[woocommercebot]

This PR is a cherry-pick of #61678 to release/10.3.

⚠️ WARNING: This cherry-pick contained conflicts that have not been resolved. Please review the changes carefully before merging!

Original PR Description

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• I have followed the WooCommerce Contributing Guidelines and the WordPress Coding Standards.
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• I have reviewed my code for security best practices.
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Changes proposed in this Pull Request:

Towards PAYPAL-106

In this PR, I am using the league/iso3166 composer package to retrieve the two-letter country code from a three-letter code before attempting to create a PayPal Standard order. This should address some possible issues when the two-letter code would not match the three-letter version, just by truncating the string value (e.g., Uruguay (URY, UY).

Additional fixes:

• Changes the comparison for the locale code to avoid setting the first two parts unnecessarily (d0cdb09)
• Uses the existing country code length constant when handling it (a22c141)
• Logging the three-letter country code (44926e7)
• Moves the country code logic to a new private method (8b244b8)

How to test the changes in this Pull Request:

Code review. If you want to test this flow, you can follow #61034 to see if no regression was introduced.

Testing that has already taken place:

Changelog entry

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Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Fix - Fixes an existing bug
• Add - Adds functionality
• Update - Update existing functionality
• Dev - Development related task
• Tweak - A minor adjustment to the codebase
• Performance - Address performance issues
• Enhancement - Improvement to existing functionality

Message

Attempts to identify the PayPal two-letter country code from a three-letter code using the league/iso3166 composer package, and applies minor additional fixes

Changelog Entry Comment

Comment

[github-actions]

Testing Guidelines

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[github-actions]

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