Site Assembler: Remove margins between the header, content and footer

[BogdanUngureanu]

Related to #78097

Proposed Changes

• Remove the margins for the content blocks so that there's no spacing between header, content and footer

Why are these changes being made?

• Bugfixing

Testing Instructions

• Access the assembler /setup/with-theme-assembler/patternAssembler?siteSlug={ YOUR SITE }
• Add a header, two section patterns, and a footer. Choose patterns with a background color, not white background, so it's easier to see if there are gaps
• Verify that there aren't gaps between patterns in the assembler large preview
• Click "Continue" and you will land on the editor
• Verify you don't see any gaps between header and footer patterns in the editor
• Go to /plugins
• Select Bakery RMT
• Land in the launchpad
• Notice that there aren't any white spaces between the header and content

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-115016

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-115016&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-115016&env=a8c-for-agencies

[matticbot]

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

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

• editing-toolkit
• odyssey-stats

To test WordPress.com changes, run install-plugin.sh $pluginSlug fix/site-assembler-block-margin on your sandbox.

[matticbot]

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

App Entrypoints (~37 bytes added 📈 [gzipped])

name           parsed_size           gzip_size
entry-stepper        +71 B  (+0.0%)      +37 B  (+0.0%)

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

Sections (~66 bytes added 📈 [gzipped])

name                parsed_size           gzip_size
subscribers               +71 B  (+0.0%)      +34 B  (+0.0%)
staging-site              +71 B  (+0.0%)      +34 B  (+0.0%)
sites-dashboard           +71 B  (+0.0%)      +34 B  (+0.0%)
site-monitoring           +71 B  (+0.0%)      +34 B  (+0.0%)
site-logs                 +71 B  (+0.0%)      +34 B  (+0.0%)
settings                  +71 B  (+0.0%)      +34 B  (+0.0%)
hosting-features          +71 B  (+0.0%)      +34 B  (+0.0%)
hosting                   +71 B  (+0.0%)      +34 B  (+0.0%)
home                      +71 B  (+0.0%)      +34 B  (+0.0%)
github-deployments        +71 B  (+0.0%)      +34 B  (+0.0%)
earn                      +71 B  (+0.0%)      +32 B  (+0.0%)
checkout                  +71 B  (+0.0%)      +34 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.

Async-loaded Components (~67 bytes added 📈 [gzipped])

name                                                 parsed_size           gzip_size
async-load-masterbar-launchpad-navigator                   +71 B  (+0.1%)      +33 B  (+0.2%)
async-load-design                                          +71 B  (+0.0%)      +34 B  (+0.0%)
async-load-calypso-my-sites-stats-pages-subscribers        +71 B  (+0.1%)      +33 B  (+0.1%)

React components that are loaded lazily, when a certain part of UI is displayed for the first time.

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.

[mmtr]

Works great!

Before	After