E2E: Check homepage can be edited on Gutenberg after sign up

[mmtr]

Changes proposed in this Pull Request

Adds an extra step to the sign up for a free/premium site tests that verifies there are no block errors when editing the homepages of the new created sites.

Fixes #38383

[matticbot]

Test live: https://calypso.live/?branch=update/e2e-signup-gutenberg

[matticbot]

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

Sections (~24 bytes added 📈 [gzipped])

name         parsed_size           gzip_size
woocommerce        +29 B  (+0.0%)      +13 B  (+0.0%)
plans              +29 B  (+0.0%)      +11 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 (~47 bytes added 📈 [gzipped])

name                                                         parsed_size           gzip_size
async-load-my-sites-checklist-wpcom-checklist-component-jsx        +54 B  (+0.0%)      +21 B  (+0.1%)
async-load-design-playground                                       +29 B  (+0.0%)       +9 B  (+0.0%)
async-load-design-blocks                                           +29 B  (+0.0%)       +4 B  (+0.0%)
async-load-design                                                  +29 B  (+0.0%)      +13 B  (+0.0%)

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.

[gwwar]

Thanks @mmtr ! Code here looks good, I also confirmed that the selector is correct for an invalid block.