Add title, description and gatewayId for express payment methods

[alexflorisca]

This PR ads title, description and gatewayId props to express payment methods to be displayed in the editor. These are used to display the available express payment methods to a merchant, once they click on the express checkout block.

This is parallel work with woocommerce/woocommerce#50791 and the feature/express-payment-improvements branch should be used to test. However this should also work with the current release of WC, and can be safely merged and released before the work in Core is released.

If these props are no provided, the name is used instead and the list will look like this:

After this PR, the list should look like this:

The link for the Stripe payment method should take you to the Stripe settings.

Testing instructions

1. Visit the checkout page in the editor
2. Click on the express payment block
3. See on the right hand sidebar that the list of Express Payment methods shows, and that the Stripe method have a title, description and the link goes to the Stripe settings page.
4. Smoke test with current WC version and make sure the express method still works as expected.

---

• 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)

[wjrosa]

Code is good, and it works as expected!

3. See on the right hand sidebar that the list of Express Payment methods shows, and that the Stripe method have a title, description and the link goes to the Stripe settings page.

It does send me to the Stripe settings page 👍 .

4. Smoke test with current WC version and make sure the express method still works as expected.

I was able to process a payment with it:
https://github.com/user-attachments/assets/9d2094b0-e7ea-4cdb-9840-db48f09549dd
https://github.com/user-attachments/assets/6a833110-de5e-44f4-b1ff-ce89e07ebda3