Remove duplicate views: Redirect from Calypso Pages to WP Admin Pages

[mmtr]

Part of #95620

Proposed Changes

Redirects from /pages/:site to /wp-admin/edit.php?post_type=page if the user participates in the "Remove duplicate views" experiment

Why are these changes being made?

Because even if the Pages menu already links to WP Admin, some users might access the Calypso URL directly, so we want to ensure that these users land in WP Admin.

Testing Instructions

• Assign yourself to the treatment variant of the experiment: 22129-explat-experiment
• Use the Calypso live link below
• Go to /pages/:site for a site with the default admin interface
• Make sure it redirects to WP Admin

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)?

[matticbot]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-129344

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-129344&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-129344&env=a8c-for-agencies

[matticbot]

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

Sections (~13 bytes added 📈 [gzipped])

name   parsed_size           gzip_size
pages        +36 B  (+0.0%)      +13 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

• blaze-dashboard
• notifications
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug update/remove-duplicate-views-redirect-pages on your sandbox.