E2E - Ads Paid Campaign Step 1 - Connect Ads Account

[jorgemd24]

Changes proposed in this Pull Request:

Closes part of #2070.

This PR includes E2E tests for the initial stage of setting up an Ads Campaign, which involves connecting the accounts.

Detailed test instructions:

1. Follow these steps to set up the e2e env: https://github.com/woocommerce/google-listings-and-ads#e2e-testing
2. Run npm run test:e2e -- ./tests/e2e/specs/add-paid-campaigns/step-1-accounts.test.js, the test should pass.
3. Or, run npm run test:e2e-dev -- ./tests/e2e/specs/add-paid-campaigns/step-1-accounts.test.js, check the test in the chromium step by step.
4. Run npm run test:e2e to make sure all tests are passed. (The tests associated with the gtag event are currently failing, but there has already been a fix implemented in this PR E2E Tests failing with WooCommerce 8.1.0 #2095)

Changelog entry

Dev - E2E - Ads a paid campaign Step 1 - Connect Ads Account

[ianlin]

Thanks for adding the tests of connecting ads account. They covered most of the scenarios and tests had passed on my local. I left some comments about separating tests so it would be a bit more explanatory.

[jorgemd24]

Thanks @ianlin for your suggestions, I addressed all of them! This is ready for another round, thanks!

[ianlin]

Thanks for the extra changes, LGTM. 👍