Add block version of Blank Canvas to FSE design picker

[zaguiini]

Changes proposed in this Pull Request

• Update available-designs-config.json to include blank canvas block theme.
• Blank Canvas is a selectable theme in the /new FSE beta onboarding design picker

Blockers

• ✅ No headstart necessary
• ✅ No demo URL necessary
• ✅ Network-activated

Screenshots

Testing instructions

• Apply branch to local calypso dev environment
• Visit http://calypso.localhost:3000/new/beta
• Enroll in the FSE beta
• Pick a free test domain
• Verify that Blank Canvas is a selectable theme
• Create a site with Blank Canvas enabled and smoke test the theme

Related to #58663.

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-25028

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-25028&env=jetpack

[matticbot]

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

App Entrypoints (~21 bytes removed 📉 [gzipped])

name                 parsed_size           gzip_size
entry-gutenboarding       +242 B  (+0.0%)       +2 B  (+0.0%)
entry-main                 -68 B  (-0.0%)      -41 B  (-0.0%)

Common code that is always downloaded and parsed every time the app is loaded, no matter which route is used.

Sections (~4249 bytes added 📈 [gzipped])

name             parsed_size           gzip_size
comments              +465 B  (+0.1%)     +310 B  (+0.2%)
media                 -362 B  (-0.0%)     -403 B  (-0.1%)
signup                +242 B  (+0.1%)      +20 B  (+0.0%)
jetpack-connect       +242 B  (+0.0%)      +20 B  (+0.0%)
accept-invite         +242 B  (+0.1%)      +20 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.

[jeyip]

Smoke Testing Theme

Requirements

Tested both the editor + frontend

Default Content

• No broken blocks on initial load

Block Patterns

• "Gallery with description and a button" pattern looks like its preview
• "Link in Bio" pattern looks like its preview
• "Talk to the host" pattern looks like its preview

Global Styles

• Typography font size, line height, and font weight changes behave as expected
• Background color, text color, and link colors changes behave as expected
• Per block global styles (typography + colors) for the Post title block behave as expected

Block Settings

• Typography font size, line height, and font weight block settings changes behave as expected
• Background color, text color, and link color block settings changes behave as expected

[jeyip]

A few things to note:

• The blank canvas theme displays in the design picker as expected. We discussed renaming the theme though p1639501720216300/1639501360.215400-slack-CHN6J22MP. I'm unsure if we should wait to release this PR or if it's a non-issue.
• It appears as if this theme isn't network activated yet, so we'll probably want to do that as well.
• I think we may want to wait until this PR is merged before displaying block themes to users Site Editor: Display editor menu item by default for block themes #58932. It enables the site editor for block themes by default since block themes don't have access to a functional customizer.

Otherwise, everything else lgtm!

[creativecoder]

This is blocked until the new version of Blank Canvas is fully launched (theme slug finalized, theme network activated, previous version deprecated, etc.).

[zaguiini]

Still not network activated Finally!

More discussion on p1641331738434800/1641330580.431200-slack-CHN6J22MP.

[vindl]

LGTM!