Dotcom Pages Modal: Update order of patterns to show theme patterns first

[miksansegundo]

Related to pdKhl6-37D-p2#comment-6213

Proposed Changes

• Update the order of patterns to show theme patterns first

BEFORE	AFTER

Next tasks for the pages modal

Post a P2 with these and more opportunities to improve this modal:

• Order page categories using the same order as in Assembler
• Add a custom hook to allow disabling the modal and show the core modal instead
• Improve the layout to list patterns horizontally rather than vertically:
  • so all theme patterns can appear in the same row
  • this will improve the loading effect too
  • the pattern explorer in core seems to work in this way and uses the height of the taller pattern for the row

Testing Instructions

• Sandbox a site
• Patch this PR in your sandbox with install-plugin.sh etk fix/add-page-modal
• Active TT4 in your site or any other theme with full-page patterns
• Create a new page from the admin { SITE }/wp-admin/post-new.php?post_type=page
• Verify the page patterns appear at the top of any of their categories

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• https://wpcalypso.wordpress.com/devdocs/docs/testing/index.md 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-104779

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-104779&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-104779&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

• editing-toolkit
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug fix/add-page-modal on your sandbox.

[fushar]

Tested and works as described!

[miksansegundo]

Next tasks are related to WordPress/gutenberg#56944

For the curious, WebKit is pushing the creation of a native Masonry layout. See https://webkit.org/blog/15269/help-us-invent-masonry-layouts-for-css-grid-level-3/