i18n: Extract strings from external @wordpress/* dependencies

[yuliyan]

Related to:

• 848-gh-Automattic/i18n-issues
• 827-gh-Automattic/i18n-issues
• 821-gh-Automattic/i18n-issues

Proposed Changes

• Extract translatable strings from @wordpress/* packages in node_modules and merge them with calypso-strings.pot.

Ideally, we'd be using the tree shaking data to filter out the strings that are not used in Calypso (see the initial implementation), but it's only available after building the app, which is not the case for the Translate job in TeamCity.

Why are these changes being made?

• Some of the @wordpress/* packages use translatable strings, but the node_modules directory is completely ignored from scanning.
• With the changes introduced in this PR, we introduce an additional scanning for translatable strings that will look into the node_modules/@wordpress/* directories and ensure the strings can be translated from within Calypso.

Testing Instructions

• Code review.
• Inspect the artifacts from the Translate job in TeamCity.

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-114557

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-114557&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-114557&env=a8c-for-agencies

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

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 update/i18n-extract-strings-from-external-wordpress-dependencies on your sandbox.

[d-alleyne]

Confirmed that the strings are added to the calypso-strings.pot, specifically "No results", from Automattic/i18n-issues#848