418: WP GraphQL Newsletter Data

[rpeterman-gp]

Closes #418

• fetch newsletter data from WP GraphQL API
• update comments of various files for accuracy and consistency.

To Review

• [x] Checkout and update WP landomain branch.
• [x] Create "Critical State" newsletter using settings from Drupal admin.
• [x] Edit Main Nav menu. Replace Top of the World and Critical State custom links to use use Newsletter reference menu items.
• [x] Checkout Branch.
• [x] Run yarn.
• [x] Run yarn dev:start.
• [x] Go to localhost:3000.

...then...

• [x] Use main menu to navigate to Top of the World newsletter page.
• [x] Ensure page loads as expected.
• [x] Ensure you can subscribe to the newsletter.
• [x] Use main menu to navigate to Critical State newsletter page.
• [x] Ensure page loads as expected.
• [x] Ensure you can subscribe to the newsletter.

[brandonhundt]

@rpeterman-gp The only thing I haven't been able to confirm is the email address reaching the subscriber list in Campaign Monitor. Otherwise this looks good.

[rpeterman-gp]

@brandonhundt The subscription logic did not change from before. As long as the list id's entered into WP are the same as the values in Drupal, subscriptions should work. The success message you see after submitting means the subscription requests to the CM API returned that the subscription was successful.