Reader Onboarding: Add load more results functionality

[DustyReagan]

Related to https://github.com/Automattic/loop/issues/188

Proposed Changes

• This PR enables the "Load more recommendations" button in Reader Onboarding.
• It does this by creating a list of 18 recommendations (a combination of hand-curated and API loaded) then displays 6 recommendations at a time. Clicking "Load more recommendations" loads the next 6 recommendations or starts over from the begining.

Screen.Recording.2024-10-21.at.9.45.59.AM.mp4

Why are these changes being made?

• Push reader onboarding project forward.

Testing Instructions

• Go to /read?flags=reader/onboarding
• Click "Discover and subscribe to sites you'll love"
• Click "Load more recommendations". You should see 6 more recommendations related to the tags you're following.
• If you continue clicking "Load more recommendations," you'll eventually get a "Start over" link, which will loop the recommendations.
• Try breaking it (some things to check)
  • The first recommendation should always be selected by default if the user hasn't selected one.
  • Changing tags should re-load a new set of recommendations
  • Refreshing the browser should load the first page of recommendations with the first recommendation selected by default.

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-122361

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-122361&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-122361&env=a8c-for-agencies

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• notifications

To test WordPress.com changes, run install-plugin.sh $pluginSlug try/reader-onboarding-more-results on your sandbox.

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~120 bytes added 📈 [gzipped])

name    parsed_size           gzip_size
reader       +317 B  (+0.0%)     +120 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[eoigal]

Do we want to have a hard limit on the number of suggested blogs/sites? I was wondering if you want to try and implement a page_handle to paginate the results but maybe this is something we can come back to?

[eoigal]

Works as advertised. We can maybe look at supporting page_handle when requesting related cards (with recommended blogs) down the line.