Feature: add a checkbox option to keep the PayPal webhooks after disconnect the account

[glaubersilva]

Resolves GIVE-854

Description

This PR adds an option to keep the PayPal webhooks config when disconnecting an account, this way we can keep receiving webhook events, including subscription renewals, from the old account.

Affects

PayPal donations, especially the recurring donations.

Visuals

Demo video: https://www.loom.com/share/4bd1ad7a2ecc48d4b875f797425ee30e?sid=258ede42-918b-4342-991a-3f989ed22ff1

Testing Instructions

1. Connect your PayPal sandbox account;
2. Check if the give_paypal_commerce_sandbox_webhook_config is present in your DB
3. Disconnect your PayPal sandbox account;
4. Make sure the give_paypal_commerce_sandbox_webhook_config keeps present in your DB

To check if the give_paypal_commerce_sandbox_webhook_config is present in your DB, use the following query:

SELECT * FROM `wp_options` WHERE `option_name` = 'give_paypal_commerce_sandbox_webhook_config'

Pre-review Checklist

• Acceptance criteria satisfied and marked in related issue
• Relevant @unreleased tags included in DocBlocks
• Includes unit tests
• Reviewed by the designer (if follows a design)
• Self Review of code and UX completed

[JasonTheAdams]

The code looks good to me! I've reached out to @Benunc for a copy check on this. Let's also do a quick DQA on this with @jdghinson before sending it to QA.

[glaubersilva]

@jdghinson I recorded a short video demonstrating the visual changes implemented in this PR and would like to get your review on it, here is the link: https://www.loom.com/share/b0dd84e1ba1e4d709e5f1509f6ce256e?sid=50f462e5-62e2-434f-bb85-f9bc7fae7a75

If you need a zip file to install it and check closer, let me know.

[jdghinson]

All good!

[rickalday]

Passed manual QA tests.