Added filter to update Level 3 data

[peterfabian]

Allow filtering level 3 data

This PR adds support to allow the use of WooCommerce Gift cards to pay for order partially with full support of Level 3 data, with the rest being paid by another payment method provided by Stripe. This previously failed due to Level 3 data mismatch.

Description

Together with https://github.com/woocommerce/woocommerce-gift-cards/pull/822 adds support for gift cards to be used as discounts with full support for Level 3 data while using Stripe to pay for the remaining amount (not covered by the gift card).

More background discussion available at p1718202231605999-slack-C3NCP7ZJ6

A similar chance is being done also in WooPayments: Automattic/woocommerce-payments#9053

Changes proposed in this Pull Request:

A minimal change: adds filter wc_stripe_payment_request_level3_data to allow updating Level 3 data for Stripe so that the data matches and order can be processed.

Haven't added tests since we'd be only testing WordPress filtering.

Testing instructions

Please check https://github.com/woocommerce/woocommerce-gift-cards/pull/822.

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• Covered with tests (or have a good reason not to test in description ☝️)
• Added changelog entry in both changelog.txt and readme.txt (or does not apply)
• Tested on mobile (or does not apply)

Post merge

• Added testing instructions to the Release Testing Instructions wiki page (or does not apply)
• Added the needs docs label (or does not apply)
• Included this PR in the Release Thread scope (or does not apply)

[james-allan]

Changes look good to me. Thanks for the PR @peterfabian!