A4A: Add Hosting page v3 feature flag.

[jkguidaven]

This PR introduces a new feature flag for the Hosting page v3. In addition, it includes a new HostingOverviewV3 component to facilitate testing, which will eventually contain the new implementation.

Closes https://github.com/Automattic/automattic-for-agencies-dev/issues/1544

Proposed Changes

• Add a4a-hosting-page-redesign-v3 and activate it in the Development and Horizon environments.
• Add a HostingOverview3 component that will be loaded when the feature flag is enabled.

Why are these changes being made?

• This is part of the 'In-product Hosting page v3' project.

Testing Instructions

• Use the A4A live link and go to the /markplace/hosting page.
• Confirm you see the empty page being loaded. See screenshot above.
• Test that when adding ?flags=-a4a-hosting-page-redesign-v3 in the URL, the current design is loaded.

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 UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• 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-126562

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126562&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126562&env=a8c-for-agencies

[matticbot]

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

Sections (~109 bytes added 📈 [gzipped])

name                          parsed_size           gzip_size
a8c-for-agencies-marketplace       +810 B  (+0.1%)     +109 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.

[matticbot]

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

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

• notifications
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug add/a4a/hosting-page-v3-feature-flag on your sandbox.

[cleacos]

LGTM!

[cleacos]

It's approved, but I was wondering if we could add something to have both versions or a direct link to restore the previous version, deactivating the flag for the Horizon/Development environments. For example, we could need to update something quickly in the current version from the current version or maybe perform some tests for other tasks.

[jkguidaven]

It's approved, but I was wondering if we could add something to have both versions or a direct link to restore the previous version, deactivating the flag for the Horizon/Development environments. For example, we could need to update something quickly in the current version from the current version or maybe perform some tests for other tasks.

Good point! In case this becomes a problem, we could create a separate link for the new hosting page. For now, I'll leave this as is and avoid additional code we need to clean up later once we release the project.