[Issue] Add missing "VAT Number" field to customer registration page

[m2-assistant]

This issue is automatically created based on existing pull request: #31321: Add missing "VAT Number" field to customer registration page

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Description

This commits makes "VAT Number" field visible when customer/create_account/vat_frontend_visibility is enabled.
The code was copied from nearby address/edit.phtml template.

Manual testing scenarios

1. Enable Show VAT Number on Storefront option at Stores > Configuration > Customers > Customer Configuration > Create New Account Options > Show VAT Number on Storefront
2. Navigate to frontend and add some product to the cart.
3. Proceed to Multishipping checkout and select "Create Account" option
4. Address fields are shown but "VAT Number" field is missing.

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[m2-assistant]

Hi @krishprakash. Thank you for working on this issue.
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[krishprakash]

@magento give me 2.4-develop instance

[magento-deployment-service]

Hi @krishprakash. Thank you for your request. I'm working on Magento instance for you.

[magento-deployment-service]

Hi @krishprakash, here is your Magento Instance: https://44d9708e09d0833566fb4827bd082187-2-4-develop.instances.magento-community.engineering
Admin access: https://44d9708e09d0833566fb4827bd082187-2-4-develop.instances.magento-community.engineering/admin_696d
Login: 622facfb
Password: 07c8fc59ba98